Electron confinement-enhanced green InP-based quantum dots for active-matrix LEDs displays

Domain: physics
Published: 2026-02-27
Editorial outcome: major_revision

Abstract
The facet-selective growth of shells on green InP-based quantum dots results in their inferior electron confinement capabilities, posing a challenge for the realization of completely cadmium-free quantum dot light-emitting diode displays. Here, we develop a surface energy homogenization strategy based on ligand adsorption using n-octylamine and diphenylphosphine selenide, effectively suppressing selective growth of ZnSe on the InP (111) facet, resulting in strongly electron-confined InP/ZnSe/ZnS quantum dots with a quantum yield exceeding 92% and a full-width at half-maximum of 35 nm. The resulting quantum dot light-emitting diodes achieve a peak external quantum efficiency of 23.50% and a luminance exceeding 1.4×10^5 cd m^-2, with a 107.5-fold increase in device lifetime. Utilized asymmetric wettability-mediated assembly strategy, we achieved quantum dot arrays with an impressive resolution of 8460 PPI. Furthermore, integrating the quantum dots into an active-matrix LED display, we successfully demonstrate the display of both static and dynamic images.

Introduction
Quantum dot light-emitting diodes (QLEDs) have emerged as a prominent technology for next-generation display and lighting applications, owing to their exceptional attributes such as low power consumption and high color purity 1–4. For a prolonged period, the most advanced QLEDs have predominantly relied on cadmium (Cd)-based quantum dots (QDs) from the II-VI group 5–8. However, the inherent toxicity of Cd has significantly hindered their large-scale commercial adoption. As a result, indium phosphide (InP)-based QDs have gained considerable attention as viable substitutes for Cd-based QDs. To date, the highest reported external quantum efficiencies (EQEs) for red and green InP-based QLEDs have reached 26.6% and 26.7%, respectively 9,10. Despite this promising progress, the facet-selective growth of shell layers during the synthesis of InP-based QDs presents a substantial challenge for further advancing InP-based QLEDs to compete with their Cd-based counterparts 11,12.

Recent studies have clearly demonstrated that the inferior performance of green InP-based QLEDs is primarily due to insufficient electron concentration, a key finding that deepens the understanding of green InP-based QLEDs 10. In comparison to CdSe-based QDs, InP-based QDs exhibit a lower effective electron mass (0.07 m_0 versus 0.13 m_0, where m_0 denotes the free electron mass) 2, necessitating a higher degree of shell uniformity to enhance electron confinement 4,13. ZnSe has emerged as the preferred shell material for epitaxial growth on InP cores, due to its favorable electronic structure (type I), comparable crystal structure (zincblende), and matched lattice parameters, with lattice parameters of InP, CdSe, and ZnSe being 5.87Å, 6.08Å, and 5.67Å, respectively 12,14,15. These attributes facilitate epitaxial growth of ZnSe on InP cores. However, ZnSe tends to show facet-selective growth on InP cores, which leads to stronger electron delocalization that deviates from the spherical ZnSe shell model 16. Existing studies suggest that adjusting the reaction temperature and stabilizing the (111) facet can mitigate this selective growth 11,12, but a deeper understanding of the mechanism underlying isotropic growth of ZnSe and its effects on QLED performance remains elusive.

Here, we develop a surface energy homogenization strategy that effectively passivates the highly reactive In^3+ on the InP (111) facet using a combination of n-octylamine and diphenylphosphine selenide (DPP-Se) ligands, leading to homogenization of the surface energies across all three facets and achieving uniform shell growth. The prepared InP/ZnSe/ZnS QDs exhibit strong electron confinement and demonstrate excellent optical performance, including a photoluminescence quantum yield (PLQY) exceeding 92% and a full-width at half-maximum (FWHM) of 35 nm. When integrated into QLEDs, they exhibit a peak EQE of 23.50% and a peak luminance exceeding 1.4×10^5 cd m^-2. The enhanced electron confinement of these QDs also mitigates electron leakage-induced damage to the hole transport layer (HTL), resulting in a 107.5-fold increase in device lifetime. Furthermore, through the asymmetric wettability-mediated assembly strategy 17–19, we fabricate high-resolution QLED devices and reduce the pixel size to 1.5 μm, achieving an impressive resolution of 8,460 pixels per inch (PPI). The high-resolution devices exhibited minimal performance degradation upon size reduction (from 20 μm to 1.5 μm), maintaining an average peak EQE exceeding 20% and exhibiting comparable performance to thin-film devices. Finally, by integrating the QDs into an active-matrix LED display, we successfully demonstrate the display of both static and dynamic images.

Results
Synthesize quantum dots with strong electron confinement
The facet-selective growth of ZnSe on InP cores is one of the factors impeding the synthesis of strongly electron-confined (SEC) InP-based QDs 2,11. This facet-selective growth results in the formation of weakly electron-confined (WEC) InP-based QDs with irregular tetrapod shape (Fig. 1a, top). On one hand, the tetrapod QDs are unable to effectively confine electrons within the core for radiative recombination with holes, leading to electron delocalization and capture by surface traps, which induces severe non-radiative recombination and spectral broadening 11. On the other hand, when WEC InP-based QDs are integrated into QLED devices, they result in significant charge leakage (Fig. 1b, top). The highly delocalized electrons in the InP-based QD layer recombine with holes in the HTL, not only causing pronounced parasitic emission peak in the electroluminescence (EL) spectrum 20,21, but also leading to the degradation of the HTL 21–23. These issues severely constrain the EQE and the operational lifetime of the devices 24. In contrast, the SEC InP-based QDs obtained from uniform shell growth not only effectively suppress electron delocalization (Fig. 1a, bottom), but also inhibiting charge leakage and thereby enhancing device performance (Fig. 1b, bottom) 20.

To delve into the mechanism of facet-selective growth of ZnSe on InP cores, surface energy simulations were conducted using density functional theory (DFT) (Supplementary Fig. 1). The calculated results indicate that the surface energies of the (111), (100) and (110) facets are 0.256 eV Å^-2, 0.187 eV Å^-2, and 0.068 eV Å^-2, respectively, with the (111) and (100) facets exhibiting significantly higher surface energies than the (110) facet. This discrepancy is attributed to the In-rich state on the (111) and (100) facets, where the (111) facet demonstrates greater instability and reactivity due to high density of surface dangling bonds 11,25. In contrast, the (110) facet forms a self-passivated surface, with stoichiometric cations In^3+ and anions P^3- rendering it the lowest energy 26,27. To modulate the surface energy, the use of short-chain amine and organophosphine ligands was adopted as an effective strategy 28,29. DFT calculations were employed to compare the adsorption effects of three different ligand combinations: oleic acid (OA) with tri-n-octylphosphine (TOP)-Se, n-octylamine with TOP-Se, and n-octylamine with DPP-Se (Supplementary Fig. 2). The results revealed that the combination of n-octylamine with DPP-Se (Fig. 1c) can most effectively homogenize the surface energies of the (111), (100) and (110) facets, with specific values presented in Fig. 1d and Supplementary Table 1. Additionally, the formation energies of the three ligand combinations attached onto three facets were calculated (Fig. 1e and Supplementary Table 1). The results show that the formation energy of the n-octylamine with DPP-Se combination on the (111) facet (−38.98 eV) is significantly lower than that on the (100) facet (−14.48 eV) and (110) facet (−0.94 eV), and also lower than that of the other two ligand combinations. This suggests that the n-octylamine with DPP-Se combination is more likely to bind to the (111) facet, thereby facilitating the mitigation of the epitaxial growth rate of ZnSe on the (111) facet 30.

We synthesized InP cores according to a previously reported method with some modifications (Supplementary Notes 1 and 2). The InP cores exhibit a first exciton absorption peak at 445 nm with a valley-to-depth (V/D) ratio of 0.47 (Supplementary Figs. 3 and 4). Based on the computational results, we employed three different ligand combinations—OA with TOP-Se, n-octylamine with TOP-Se, and n-octylamine with DPP-Se—during the ZnSe growth process (Fig. 1f), followed by the growth of ZnS shells to obtain three types of InP/ZnSe/ZnS QDs (see details in “Methods”). Transmission electron microscopy (TEM) images reveal that the morphologies of the QDs transition from a tetrapod shape to an intermediate shape and finally to a spherical shape (Fig. 1g and Supplementary Fig. 5). Energy-dispersive spectroscopy element mapping demonstrates the distribution of Se in QDs synthesized with OA and TOP-Se closely aligns with the pod-like morphology, demonstrating more pronounced facet-selective growth as the ZnSe shell thickens (Supplementary Fig. 6) 31,32. In contrast, the InP/ZnSe/ZnS QDs synthesized using n-octylamine with DPP-Se possess a highly symmetric core/multishell structure with uniform ZnSe shell growth (Supplementary Fig. 7). In addition, X-ray diffraction in Fig. 1h also shows that the (111) facet diffraction peak intensity of InP/ZnSe/ZnS QDs synthesized with a combination of n-octylamine and DPP-Se ligands is the lowest, which is consistent with the high-resolution TEM images analysis (Supplementary Fig. 8). These observations collectively indicate that our ligand combination successfully suppresses the selective growth of ZnSe on the (111) facet 31. Fourier-transform infrared spectra and X-ray photoelectron spectroscopy (XPS) of N 1s and In 3d confirm that DPP and n-octylamine are successfully introduced and coordinated on the surface of the QDs (Supplementary Fig. 9).

Optical performance characterization of quantum dots
During the synthesis process, the InP/ZnSe QDs synthesized using the combination of n-octylamine and DPP-Se exhibit higher PLQY (Supplementary Figs. 10 and 11a) and a significantly higher V/D value of 0.59 compared to 0.22 for that synthesized with OA and TOP-Se (Fig. 2a), indicating a more effective and uniform growth of ZnSe. Additionally, the InP/ZnSe/ZnS QDs synthesized with n-octylamine and DPP-Se did not exhibit significant spectral broadening during the ZnSe shell layers growth (Fig. 2b), ultimately exhibiting a smaller peak redshift (537 nm) and a narrower FWHM (35 nm), in comparison to the QDs synthesized with OA and TOP-Se (542 nm, FWHM=42 nm) (Fig. 2c and Supplementary Fig. 11b). We employed transient absorption spectroscopy to analyze the exciton dynamics of two types of QDs (Fig. 2d). Both of the QDs exhibit two distinct bleaching peaks at ~510 nm and ~445 nm, which are attributed to the 1S_e-1S_3/2 and 1S_e-2S_3/2 transition, respectively 33,34. The bleaching recovery dynamics of ground-state bleaching (GSB) peak (~510 nm) of two types of QDs were analyzed by fitting the decay curves with a tri-exponential function (Supplementary Table 2). The GSB of QDs synthesized with OA and TOP-Se shows pronounced bleaching and rapid decay dynamics, indicating poor defect passivation at the InP core and ZnSe interface 35. In contrast, the GSB peak of QDs synthesized with n-octylamine and DPP-Se ligands demonstrates slower decay dynamics, suggesting effective exciton recombination 36,37. These characteristics collectively demonstrate that the combination of n-octylamine and DPP-Se ligands during synthesis enables the uniform growth of the ZnSe shell, resulting in uniform size distribution and strong electron confinement.

The fluorescence decay lifetimes of the two types of QDs were obtained using time-resolved photoluminescence (TRPL) spectroscopy (Fig. 2e). Compared to the photoluminescence (PL) lifetime of WEC QD solution (57.95 ns), the SEC QD solution exhibited a longer PL lifetime of 84.83 ns, indicating effective passivation of defects and suppression of non-radiative recombination 38. Additionally, the SEC QDs achieved a PLQY of 92.28%, significantly surpassing the 64.46% of the WEC QDs, and exhibited superior photostability under UV irradiation (Fig. 2f and Supplementary Table 3). This enhanced performance is attributed to the superior electron confinement, which effectively isolates electrons from surface traps and thereby significantly reducing non-radiative recombination via exciton-surface coupling 39,40. Concurrently, this confinement promotes greater overlap of electron and hole wavefunctions, which enhances the binding energy and boosts the radiative recombination rate. This dual mechanism—promoting radiative recombination while suppressing non-radiative decay—is further corroborated by the higher PL intensity of the SEC QDs at an equivalent optical density (Fig. 2g) and their exceptional stability in temperature-dependent PL measurements (Fig. 2h and Supplementary Fig. 12).

Device performance characterizations
Next, we integrated the two types of QDs as emission layers into QLED devices (ITO/PEDOT:PSS/PF8Cz/QD/ZnMgO/Al) and demonstrated the enhanced EL performance of the QLED devices based on SEC QD films compared to those based on WEC QD films (see details in “Methods” and Supplementary Note 3). Cross-sectional TEM image of the QLED devices revealed the sequential stacking of the functional layers (Fig. 3a). Surface roughness of the two QD films was characterized using atomic force microscopy. Due to the irregular tetrapod shape of the WEC QDs, the QDs were randomly arranged within the film, resulting in a rough surface, with the atomic force microscopy images showing a surface roughness (R_q) of 4.37 nm (Supplementary Fig. 13a, b). In contrast, the SEC QD films exhibited a highly uniform and smooth surface (Supplementary Fig. 13c, d), with a smaller R_q of only 0.64 nm. Additionally, the increased absorption intensity in the UV-visible absorption spectra also indicated a denser packing in the SEC QD films (Supplementary Fig. 14) 41.

The EL spectra under various voltages revealed that the EL emission peak of the QLED based on WEC QD films was located at 552 nm with a FWHM of 52 nm, whereas the EL emission peak of the QLED based on SEC QD films was located at 542 nm with a FWHM of 43 nm (Fig. 3b). The corresponding CIE coordinates (0.320, 0.658) of the SEC QLED indicated a green emission with higher color purity than the WEC QLED, which is favorable for application in ideal green displays (Supplementary Fig. 15). The EL spectra of the SEC QDs exhibit a red shift of ~5 nm compared to the PL spectra, whereas the EL spectra of the WEC QDs shows a 10 nm red shift along with significant broadening (Supplementary Fig. 16). Furthermore, in electric-field-dependent PL measurements, the WEC QDs showed a higher sensitivity to the electric field and demonstrate more pronounced PL quenching and redshift with increasing voltage compared to the SEC QDs (Supplementary Fig. 17). These observations indicate a weaker Stark effect in the SEC QDs under an electric field, which can be attributed to strong electron confinement that suppresses the delocalization of electron wavefunctions toward the shell surface 2,42. Due to the strong electron delocalization driven by the electric field, the EL spectrum of the QLED based on WEC QD films showed a parasitic emission peak (see Fig. 3c and Supplementary Fig. 18a), which is consistent with the intrinsic EL spectrum of PF8Cz (Supplementary Fig. 18b). This is attributed to highly delocalized electron leakage from the InP QD layer to the HTL, where they recombine with holes in the HTL 21,43. In contrast, the SEC QDs did not produce parasitic emission, effectively preventing charge leakage 20.

The current density-voltage-luminance (J-V-L) curves for the devices based on two types of QDs are shown in Fig. 3d. The QLED based on SEC QD films exhibited a peak luminance of 141,325 cd m^-2, which is 3.33 times higher than that of QLED based on WEC QD films (42,450 cd m^-2). Additionally, the QLED based on SEC QD films exhibited a lower current density, resulting in a higher peak EQE and peak current efficiency (Fig. 3e), reaching 23.50% and 97.26 cd A^-1, respectively. This represented a 2.8-fold improvement compared to the QLED based on WEC QD films, which exhibited a peak EQE of 8.32% and a peak current efficiency of 34.43 cd A^-1. Space charge limited current (SCLC) calculations indicate that the QLED based on SEC QD films exhibited higher hole mobility and lower electron mobility compared to the QLED based on WEC QD films (Supplementary Fig. 19a-d and Supplementary Notes 4 and 5), which is beneficial for balancing hole and electron injection. Furthermore, the trap state density of the QLED based on SEC QD films was reduced, as calculated from the trap filling limit voltage (V_TFL) (Supplementary Fig. 19e) 44,45. Capacitance-voltage (C-V) characteristics showed that the QLED based on SEC QD films exhibited a smaller capacitance compared to the QLED based on WEC QD films, indicating a reduction in charge accumulation at the interface between QD layer and the HTL/ETL (Supplementary Fig. 19f) 46. Figure 3f presented statistical data of the peak EQE for 20 QLED devices of each QD type, demonstrating good reproducibility of our devices.

Additionally, we measured the change in surface temperature of the devices over time under a constant current density, and the rise in surface temperature of the devices based on SEC QD films was significantly slower than that of the devices based on WEC QD films (Fig. 3g). For operational lifetime of QLEDs, as shown in Fig. 3h, the device based on SEC QD films exhibited a higher half-lifetime (T_50) of 32.5 h at an initial luminance of 6,470 cd m^-2. The lifetime at different luminance values was fitted using the empirical equation L_0^n × T_50 = constant (L_0, initial luminance) 10. The acceleration factors (n) were derived from the fitting of the data presented in Supplementary Fig. 20. The calculated T_50 at 100 cd m^-2 for QLEDs based on SEC QD films reached 59,151 h, representing a 107.5-fold enhancement compared to lifetime of QLEDs based on WEC QD films (T_50 ≈ 0.288 h at 6,501 cd m^-2, equivalent to T_50 ≈ 550 h at 100 cd m^-2) (Supplementary Fig. 21).

We attributed the substantially improved operational lifetime to strong electron confinement of SEC QDs, which suppressed electron leakage to HTL and mitigates HTL degradation. To confirm the impact of charge leakage on HTL degradation, we fabricated QLEDs with identical structures using two types of QDs and operated them at a constant current density of 2.0 mA cm^-2 for 20 h. The top layers were then removed to measure the absorption and photoluminescence spectra of PF8Cz before and after device operation (Supplementary Fig. 22a). The results reveal that after the same operational time, the absorption of PF8Cz in devices based on WEC QDs shows marked redshift and decrease in intensity, accompanied by a significantly enhancements in the lower-energy emissions (Supplementary Fig. 22b-d). The emergence of additional peak assigned to C=O at 288.1 eV in C 1s demonstrated that this degradation can be attributed to the electro-oxidation of fluorene units in PF8Cz to fluorenone group induced by leakage electrons (Supplementary Fig. 22e-g) 42,47. In contrast, the HTL in devices based on SEC QDs shows no evident degradation, suggesting that enhanced electron confinement helps to mitigate HTL degradation, thereby improving the operational stability of the devices. To further rule out potential interference from different ligands, we synthesized InP/ZnSe/ZnS QDs featuring a thinner ZnSe shell (~1 nm) compared to that of the SEC QDs (~2 nm), while maintaining the same ligands of n-octylamine and DPP-Se. The corresponding devices exhibited a lifetime of only T_50 ≈ 3,457 h at 100 cd m^-2 (Supplementary Fig. 23), which mainly attributed to the insufficient electron confinement of the thinner ZnSe shell. The result further confirmed that strong electron confinement is the key factor underlying the significant improvement in device lifetime.

Active-matrix light-emitting diodes displays
To investigate the application of these SEC QDs in displays, we utilized an asymmetric wettability-mediated assembly strategy to assemble the QDs into microstructure arrays and integrated them into QLED devices (Fig. 4a) 17–19. Specifically, under the confinement of a micropillar template featuring asymmetric wettability (hydrophilic top and hydrophobic sidewall) (Supplementary Fig. 24 and Supplementary Note 6), the liquid film was divided into individual capillary bridges on the top of the pillars. Accompanied by the solvent evaporation and directional dewetting, QDs deposited uniformly and assembled into microstructure arrays. The assembly process is detailed in Supplementary Fig. 25. By manipulating the concentration of the QD solution, we achieved high-quality QD arrays (Supplementary Fig. 26). Fluorescence microscopy and scanning electron microscopy images revealed that the QD microarrays exhibited uniform size and luminance (Supplementary Fig. 27). By adjusting the micropillar dimensions of the template (Supplementary Fig. 28), we successfully reduced the pixel size from 20 μm to 1.5 μm, achieving a maximum resolution of 8,460 PPI (Fig. 4b). Remarkably, statistical analysis demonstrated that our high-resolution devices maintained an average EQE above 20% across the entire pixel size range from 20 μm to 1.5 μm (Fig. 4c, d). The maximum luminance and operational lifetime of high-resolution devices were also comparable to those of thin-film devices (Supplementary Fig. 29). This maintained high performance with decreasing pixel size is attributed to controllable solvent evaporation and directed dewetting in our assembly strategy, which effectively suppresses the pronounced coffee-ring effect in spin-coating (Supplementary Fig. 30) 9,19. The uniform spherical morphology of SEC QDs and their well-ordered self-assembly enabled by this controlled assembly process collectively enables uniform EL across the high-resolution display panel (Supplementary Fig. 31). Subsequently, we successfully realized static display of high-resolution patterns (Supplementary Figs. 32 and 33).

We further integrate SEC QDs into a 1.85-inch active-matrix LED display with a resolution of 352×430, where each pixel can be independently controlled (the structure of the display panel is shown in Supplementary Fig. 34). Under the regulation of the driving current from the thin-film transistor array driving circuit, individual pixels can achieve continuous and precise grayscale tuning. Figure 4e successfully demonstrates a static image of a lizard. The enlarged fine image of the local structure of the lizard under microscope exhibits uniform luminescence between adjacent pixels at the micro level. Figure 4f and Supplementary Video 1 further presented a vivid video showing water drops flowing. The fabrication of this InP QD-based active-matrix LED displays paves the way for the widespread application of heavy-metal-free QDs in the field of display technology.

Methods
Additional details regarding the materials and methods can be found in Supplementary Information (‘Experimental section’).

Materials
Zinc acetate (Zn(OAc)_2, 99.99%), sulfur (S, 99.998%, powder), oleic acid (OA, 90%) chlorobenzene, acetone (98%) and isopropyl alcohol (98%) were purchased from Sigma-Aldrich. n-Octylamine (98%) was purchased from Macklin. Selenium (Se, 99.999%, powder), 1-octadecene (ODE, 90%) were purchased from Thermo scientific. Trioctylphosphine (TOP, 90%), diphenylphosphine (DPP, ≥ 95%), hydrogen fluoride-pyridine (HF, 70wt%), n-octane (99%) and n-hexanes (98%) were purchased from Aladdin. Ethanol (99.7%) and toluene (≥99.5%) were purchased from Sinopharm Chemical Reagent Co., Ltd. Poly((9,9-dioctylfluorenyl-2,7-diyl)-alt-(9-(2-ethylhexyl)-carbazole-3,6-diyl))(PF8Cz) was purchased from Volt-Amp Optoelectronics Tech. Co., Ltd, Dongguan, China. Poly(3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS, AI 4083) was purchased from Heraeus Deutschland GmbH & Co. KG.

Synthesis of strongly electron-confined quantum dots
The shell growth was conducted using InP cores synthesized according to the procedure in Note 2 of Supporting Information. For the growth of shell, 1 mmol of Zn(OAc)_2 and 10 mL of ODE were loaded in a 100 mL flask and purged with nitrogen and maintained at 120 °C for 30 min. Then 10 mL of n-octylamine was added into the system. The temperature was heated up to 160 °C with the as-prepared InP core in 2 ml toluene injected dropwise. Immediately, 0.12 mL of 7 wt% HF solution (see Supplementary Note 1 for the preparation process) was added and maintained the reaction for 5 min for removal of surface oxide. Then, the reaction solution was heated to 220 °C to grow the ZnSe layers. 2 mL of 0.4 M DPP-Se and 2 mL of 0.4 M Zn(OAc)_2 were injected dropwise at 220 °C and kept the reaction for 1 h. Subsequently, the reaction solution was heated to 240 °C and 2 mL of 0.4 M DPP-Se and 2 mL of 0.4 M Zn(OAc)_2 were inject dropwise for 1 h. Following the completion of this step, injected 2 mL of 0.4 M Zn(OAc)_2 and 0.5 mL of 1.0 M TOP-S into the flask and reacted for 1 h when the solution was heated to 300 °C for the growth of ZnS layers. The resulting solution was then cooled to room temperature, washed with ethanol and n-hexane three times to remove impurities, and finally dispersed in n-octane for further characterizations.

Synthesis of weakly electron-confined quantum dots
For the growth of shell, 1 mmol of Zn(OAc)_2, 10 mL of ODE and 10 mL of OA were loaded in a 100 mL flask and purged with nitrogen and maintained at 120 °C for 30 min. Then the temperature of the flask was heated up to 160 °C before the as-prepared InP Core in 2 ml toluene was injected dropwise. Immediately, 0.12 mL of 7 wt% HF solution was added and maintained the reaction for 5 min for removal of surface oxide. Then, the reaction solution was heated to 220 °C to grow the ZnSe layers. 2 mL of 0.4 M TOP-Se and 2 mL of 0.4 M Zn(OAc)_2 were injected dropwise at 220 °C and kept the reaction for 1 h. Subsequently, the reaction solution was heated to 240 °C and 2 mL of 0.4 M TOP-Se and 2 mL of 0.4 M Zn(OAc)_2 were inject dropwise for 1 h. Following the completion of this step, injected 2 mL of 0.4 M Zn(OAc)_2 and 0.5 mL of 1.0 M TOP-S into the flask and reacted for 1 h when the solution was heated to 300 °C for the growth of ZnS. The resulting solution was then cooled to room temperature, washed with ethanol and n-hexane for 3 times to remove impurities, and finally dispersed in n-octane for further characterizations.

Fabrication of devices
The indium tin oxide (ITO)-coated glass substrates were ultrasonically cleaned with detergent, deionized water, acetone, and isopropyl alcohol for 15 min each, and were then treated with O_2-plasma for 15 min. Subsequently, a hole injection layer (HIL) of PEDOT:PSS was spin-coated onto ITO substrates at 4000 rpm for 40 s, followed by annealing at 150 °C for 30 min. Then, these substrates were transferred into a nitrogen-filled glovebox for spin-coating PF8Cz, InP QDs, and ZnMgO layers. PF8Cz was prepared by spin-coating 30 μL of 8 mg mL^-1 solution in chlorobenzene at 3000 rpm for 40 s, and then baked at 120 °C for 30 min. The QDs layer was prepared by spin-coating 30 μL of 20 mg mL^-1 QD solution at 2000 rpm for 30 s and baked at 80 °C for 7 min. The ZnMgO nanoparticle solution synthesized with the method in Supplementary Note 3 was spin-coating at 2000 rpm for 30 s and baked at 60 °C for 30 min. Al electrode (with a thickness of 100 nm) was deposited by thermal evaporation under a degree of vacuum of ≈ 2.5×10^-4 Pa. Ultimately, the devices were encapsulated using UV-curable epoxy resin and cover glass in a glovebox.

The peel-off experiments were carried out on unencapsulated QLEDs in a nitrogen-filled glovebox to expose the PF8Cz layer. The Al cathode was first detached using polyimide tape. Then, the ZnMgO layer was washed away by spin-coating 30 µL of an acetic acid-ethanol solution (0.8% by volume) at 2000 rpm for 30 seconds, followed by the same process using 30 µL of pure ethanol. The QD layer was removed by spin-coating 30 µL n-octane at 2000 rpm for 30 seconds.

Fabrication of high-resolution patterned devices
The ITO-coated glass substrates were ultrasonically cleaned with detergent, deionized water, acetone, and isopropyl alcohol for 15 minutes each, and were then treated with O_2-plasma for 15 min. Subsequently, PEDOT:PSS was spin-coated onto ITO substrates at 4000 rpm for 40 s, followed by annealing at 150 °C for 30 min. Then, these substrates were transferred into a nitrogen-filled glovebox for spin-coating. The PF8Cz layer was spin-coated at 3000 rpm for 30 s using an 8 mg mL^-1 solution in chlorobenzene, followed by baking at 120 °C for 30 min. Next, fabricate photoresist pit arrays on these substrates by photolithography. Negative photoresist was spun-coated at 3000 rpm for 30 s and baked at 90 °C for 1 min. A custom mask was used to expose the photoresist on the photolithography machine for 5 s, followed by development, rinsing, and drying to create pixel pits of specific size. Then substrates with photoresist pits, 6 μL of 50 g mL^-1 QDs toluene solution and a micropillar template were integrated together (aligning each pit with each pillar on the template using the alignment system). A self-made pressure device was used to maintain proper and balanced pressure. The solution was evaporated at room temperature for 6 h to form a QDs array pattern on the substrate. Subsequently, The ZnMgO nanoparticle solutions synthesized with the method in note S3 was spin-coating at 2000 rpm for 30 s and baked at 60 °C for 30 min. Al electrode was deposited by thermal evaporation under a based vacuum of ≈ 2.5×10^-4 Pa. Ultimately, the devices were encapsulated using UV-curable epoxy resin and cover glass in a glovebox.

Characterization of materials
TEM (JEOL, 2100F, Japan) and TEM (JEOL, 7700F, Japan) were used to evaluate the size and morphology of the QDs at 200 kV accelerating voltage. UV-vis absorption and PL spectra were measured by an Ocean Optics spectrophotometer (model PC2000-ISA). All scanning electron microscopy images were tested at 10 kV and 10 μA current using the Hitachi SU8010 (Japan) instrument. The surface morphology and roughness of the QD array were measured using atomic force microscope (Bruker Nano, ICON2-SYS). The QD lattice was acquired by in-situ double spherical aberration correction transmission electron microscope (JEM-ARM300F, Japan) at an operating voltage of 300 kV. Fourier-transform infrared spectroscope (Agilent, Excalibur 3100, USA) was used to collect covalent bond vibration signals. The Edinburgh instrument FLS1000 was used to analyze the emission spectra, PLQY, and time-resolved PL spectra of QDs. All fluorescence images were captured using a microscope (Olympus DP80). X-ray diffraction data were acquired using an X-ray diffractometer (Bruker Nano Inc.) with monochromatized Cu Kα radiation (λ = 1.5406 Å). XPS spectra were measured using an ESCALAB 250Xi system. Capacitance-voltage characteristics curves were performed using a semiconductor analyzer (LakeShore 8425, 4200A-SCS, B1500) with a modulating frequency of 30 KHz. The luminescence intensity distribution of the QD array was obtained by confocal imaging microscopy (Ars iMP-LSM). Transient absorption measurements were performed using femtosecond laser pulses from an 800 nm laser beam (1 kHz pulse repetition rate, 25 fs pulse duration) generated by a regenerative amplified Ti: Sapphire laser system (Coherent Co.). The output of the amplifier was split into two streams of pulses with a beam splitter. Residual stream was directed into an ultrafast spectroscopic system (Helios pump-probe system (Ultrafast Systems) to generate the white light continuum probe beam (300-2600 nm window with various optical filters). The pump wavelength was set at 370 nm. Delaying the probe pulse relative to the pump allowed a time window of up to 5 ns. The instrument response function was determined to be ≈ 200 fs using a cross-correlation procedure. The sample was filled in a 1 mm thick quartz cell for transient absorption experiment which was continuously swayed to prevent the optical damage.

Characterization of devices
All devices were tested in a nitrogen-filled glovebox using homemade test sockets. The J-V-L curves, EL spectra, current efficiency and EQE were measured using a commercial system (XPQY-EQE-Adv from Xipu Optoelectronics Technology Co., Ltd., Guangzhou). For lifetime testing, the encapsulated samples were measured in a nitrogen environment.

DFT calculations
All calculations were carried out using the DFT with the generalized Perdew–Burke–Ernzerhof (PBE), and the projector augmented-wave (PAW) pseudopotential plane-wave method was implemented in the VASP code 48–52. A 2×2×1 Monkhorst-Pack k-point grid was used for all unit cell geometry optimization calculations. The plane-wave energy cutoff is set to 500 eV. The convergence criterion for the total energy tolerance per atom is 1×10^-6 eV atom^-1, and the maximum force tolerance is 0.02 eV Å^-1.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This manuscript presents the synthesis of InP quantum dots (QDs) and their application in QD-light emitting diode (QLED) and active matrix LED display. From the perspective of InP QDs synthesis, the authors utilized different combinations of ligands such as OA:TOP-Se, octylamine:TOP-Se, and octylamine:DPP-Se for the ZnSe shell formation to mitigate its facet-selective growth and promote the homogeneity. The final InP/ZnSe/ZnS QDs exhibited a quasi-spherical shape by using octylamine:DPP-Se combination. They implemented these InP QDs for the fabrication of QLED and an active matrix green display. The QLED exhibited a peak external quantum efficiency (EQE) of 23.50% with a life span of 59,151 h at 100 cd m-2. However, the findings of this work are not sufficiently novel, making it not suitable for consideration in Nature Communications; therefore, I do not recommend it for publication. The detailed concerns are discussed below:\n1- The authors demonstrated that using octylamine:DPP-Se, they eliminated the facet-selective growth; however, there is a rich literature available where octylamines in combination with TOP-Se have shown the growth of homogenous ZnSe shells on InP QDs, affecting the novelty of this work. For example consider the representative works below:\n[1] Nature 575, 634–638 (2019)\n[2] Nature 635, 854–859 (2024)\n2- In the XRD analysis (Fig. 1h), the authors claimed that the reduced (111) peak intensity in SEC QDs shows suppressed ZnSe growth on the (111) facet. However, the XRD peak intensities are also influenced by multiple factors, including crystal orientation, size effects, etc.\n3- While Figures 2f-h demonstrate superior photostability of SEC QDs through PLQY decay under UV irradiation, solution-phase PL intensity, and temperature-dependent PL spectra, the authors provided no mechanistic explanation linking these observations to enhanced electron confinement.\n4- Regarding the device performance, the authors attributed 107.5-fold operational lifetime enhancement in SEC QD device exclusively to suppressed electron leakage into the HTL via strong electron confinement lacks mechanistic validation. There could be other parameters involved, such as different ligands that could passivate the QDs' surface and affect their overall stability under electric field.\n5- The authors provided no experimental evidence demonstrating how electron leakage initiates HTL degradation, nor did they consider factors like interfacial defect generation across different layers.\n6- The attribution of the 430 nm parasitic peak in WEC device solely to electron leakage-induced recombination in the HTL requires further investigations. To strengthen this claim the EL spectra from PF8Cz-based control device will be helpful to verify whether its intrinsic emission aligns with the 430 nm feature.\n7- The maximum EQE of the QLED reported is 23.50% which is lower than the recent reported EQE (26.68%) for the green InP QLED, why? (Nature 635, 854–859 (2024))\n8- The FWHM of the EL spectrum increased to 43 nm, much broader than its PL spectrum, which is 35 nm. No attention is paid to this factor, like what caused such broadening, as it affects the color purity.\n9- The T50 at 100 cd m−2 for QLED based on SEC InP QDs reached 59,151 h only, whereas the recent best reported case for green InP QLED demonstrated a T95 of 89,900 h under similar brightness conditions.(Nature 635, 854–859 (2024))", "reviewer_2": "The authors report that the combined use of n-octylamine and DPP-Se enables isotropic ZnSe shell growth on InP cores, thereby enhancing electron confinement. They achieve a QY above 92%, an FWHM as narrow as 35 nm, a QLED EQE exceeding 23.5%, and a maximum brightness above 140,000 cd m⁻². They also demonstrate an asymmetric wettability-mediated assembly strategy for QD arrays with a resolution of 8,460 ppi, integrated into an AM-display prototype.\nIt is known that ZnSe tends to exhibit facet selectivity, and the facet-selective growth only has a limit for effective electron confinement as well. The authors claim that the use of n-octylamine and DPP-Se homogenizes surface energy and suppresses the (111) facet selectivity of ZnSe growth. While this approach is interesting, it should be noted that n-octylamine and DPP-Se have been frequently employed in previous studies, and the reported QY of 92% is not significantly higher than in prior literature. Similarly, the QLED EQE of 23.5% is not unprecedented, with the highest reported value for green InP devices reaching 26.7% (Ref. 10 in this manuscript). However, the reported average peak EQE of around 20% for AM-LED devices is, to the best of my knowledge, unprecedented and represents a noteworthy achievement. The relationship between ZnSe shell thickness and electron confinement has been quantitatively discussed in earlier reports (e.g., ACS Energy Letters, 5 (4), 1316-1327). A more developed interpretation in comparison to those works would strengthen the paper. In addition, evidence beyond lattice parameter analysis is needed to support the claim that facet selectivity governs ZnSe morphology development. In the present study, the QDs have an approximate overall diameter of 7 nm, with an InP core of ~2 nm and a ZnSe thickness of ~2 nm required for >95% electron confinement, plus ~0.5 nm ZnS for further confinement. These dimensions suggest a QD size near the minimal requirement. Considering that in Ref. 10 isotropic ZnSe shells of 2.5–4.5 nm thickness (overall size 8–12 nm) were successfully synthesized and used, and that this was a key improvement in that work, the shell thickness in the present study is actually smaller. Thus, it would be valuable for the authors to further highlight what is truly new here compared to previous results.\nThe reported PL and EL characteristics of the SEC and WEC QDs—PL: 537 nm (35 nm) and 542 nm (42 nm), EL: 542 nm (43 nm) and 552 nm (52 nm), with Stokes shifts of 5 nm and 10 nm (Supporting Fig. 14)—are indeed consistent with exciton delocalization effects in core/shell QDs, particularly those arising from the relatively light electron. However, this outcome is predictable, and the novelty in this context should be clarified. For example, the SEC and WEC decay times differ by ~1.4×, and the current density difference in EOD devices is ~1.6×. Given that decay times are on the nanosecond scale while current measurements are much slower, it is not immediately clear how these differences can be directly attributed to electron confinement in the QDs. A more detailed explanation would help—for instance, could EL decay time be interpreted in relation to device current density, or could PL changes under applied electric fields provide further insight? I encourage the authors to address such points in more detail.\nThe most importantly, the paper discusses tuning the InP core surface energy to control ZnSe growth and includes DFT calculations. While this addresses the earliest stage of core–shell interface formation, experimental evidence suggests that the initial ZnSe nucleation on InP surfaces tends to be relatively isotropic, even with the facet selectivity. However, the final morphology (derived from the facet selectivity) emerges more strongly as the ZnSe layer thickens (not on the InP core surface). Thus, the current interpretation may not fully capture the later stages of shell growth. It may be worth considering additional mechanisms and evidence—for example, calculating surface energies for ZnSe facets during shell growth as the shell evolves, or showing possible pathways by which lattice mismatch is accommodated as the shell evolves. These are only suggestions, and better approaches can also be suggested by authors.\nThe comparison of SEC and WEC QDs—both having relatively low QY due to less effective surface passivation—and the use of their FWHM and decay time differences to argue for electron confinement effects is not entirely convincing. Likewise, the performance difference between the corresponding QLED devices may not be sufficient as sole evidence. Clarifying how the observed effects can be distinguished from exciton or hole confinement (and attributed specifically to electron confinement) would strengthen the argument. Notably, the use of DPP-Se to control Se reactivity has been reported multiple times (e.g., Evans et al., J. Am. Chem. Soc., 132, 10973-10975, 2010), and various alkylamines have also been widely employed (Front. Chem., 6, 2018, doi:10.3389/fchem.2018.00567). A recent paper (Nature Communications, 16, 1945 (2025)) reported that combining DPP-Se with oleylamine allowed size and shape control of ZnTeSe QDs, yielding improved quality under conditions similar to those here (though n-octylamine was not used). These prior results suggest that the ligand combination in the present study is not entirely unprecedented, though the authors have applied it to produce high-quality materials. A clearer mechanistic explanation of how surface energy was tuned in this work would be beneficial.\nIn conclusion, while the manuscript presents high-quality materials and strong device results, the novelty of the synthesis approach and the proposed underlying mechanism are not yet fully convincing. I believe the work could be publishable in another journal in its current form, but for Nature Communications, additional experimental evidence and mechanistic justification would be necessary to clearly establish the claimed novelty.", "reviewer_3": "Guo et al. have synthesized strongly electron-confined green InP QDs towards heavy-metal-free ultrahigh-resolution active-matrix displays. They effectively suppress selective growth of shell on the InP (111) facet through introducing n-octylamine and DPP-Se ligands. High-performing QLEDs based on these QDs exhibit a peak EQE of 23.5%, a high luminance and long operational lifetime. Impressively, the high-resolution QLEDs achieve a compelling 8,460 PPI resolution while maintaining average peak EQEs comparable to thin-film QLEDs. I think this article is interesting and meaningful for the next-generation eco-friendly displays based on heavy-metal-free QDs. I recommend publication after the following issues are addressed.\n1. In this article, the authors mainly focus on the facet-selective growth of shell layers during the synthesis of InP-based QDs. They proposed that the synergistic effect of octylamine and DPP-Se ligands promotes uniform ZnSe shell growth, thereby effectively passivating surface defects. Although it is supported by morphological and spectroscopic data of InP/ZnSe/ZnS QDs, this article still lacks direct evidence for ligand-mediated ZnSe uniformity without additional ZnS shell. It is essential to provide comprehensive characterizations of InP/ZnSe QDs with different ligands (e.g. TEM image, PLQY data, etc.) for the validation of their mechanism. Moreover, in Supp. Fig. 7, FTIR and XPS data can only demonstrate the existence of octylamine, thus the authors need to add more data to verify the involvement of DPP ligands. More data or discussions are also needed to further evaluate the effect of octylamine and DPP-Se ligands on controlling facet-selective growth of InP/ZnSe QDs, except XRD and distribution statistics of QD size.\n2. It is particularly impressive that the SEC QD-based devices demonstrate sustained efficiency exceeding 20% across an extensive pixel size range (1.5-20 μm). For the high performance in high-resolution devices, the authors attributed it to the controlled assembly achieved through their strategy besides the inherent properties of SEC QDs. They need to provide more detailed discussions to clarify the necessity of their assembly strategy.\n3. In Supp. Fig. 15, the authors reported the carrier mobility of their core-shell QDs through hole-only/electron-only devices, which exhibit different device structures of QLED device in Fig. 3a. To ensure reproducibility of this article, they need to provide the detailed methodology in both fabrication and measurement of these devices.\n4. Other minor issues should be corrected. For example, the yellow indicators in Fig. 1a are unclear and should be optimized; The color scale in Fig. 2h lacks axis labels; The axis ranges and color bars in Supplementary Figs. 5 and 11 should be unified for better clarity; Unit formats in Supplementary Fig. 11 should be made consistent with the main text; In the figure caption of Supp. Fig. 15, electron-only devices (HODs) is misspelled."}, "author_response": "Response to Reviewers' Comments and Revised Details\nManuscript ID:NCOMMS-25-46975\nResponse to Reviewer 1:\nComment 1: This manuscript presents the synthesis of InP quantum dots (QDs) and\ntheir application in QD-light emitting diode (QLED) and active matrix LED display.\nFrom the perspective of InP QDs synthesis, the authors utilized different combinations\nof ligands such as OA:TOP-Se, octylamine:TOP-Se, and octylamine:DPP-Se for the\nZnSe shell formation to mitigate its facet-selective growth and promote the\nhomogeneity. The final InP/ZnSe/ZnS QDs exhibited a quasi-spherical shape by using\noctylamine:DPP-Se combination. They implemented these InP QDs for the fabrication\nof QLED and an active matrix green display. The QLED exhibited a peak external\nquantum efficiency (EQE) of 23.50% with a life span of 59,151 h at 100 cd m-2.\nHowever, the findings of this work are not sufficiently novel, making it not suitable for\nconsideration in Nature Communications; therefore, I do not recommend it for\npublication. The detailed concerns are discussed below:\nResponse to comment 1: We sincerely appreciate Reviewer 1’s time, effort, and\nthoroughly review on our manuscript. We acknowledge the reviewer’s concern on the\nnovelty of this work. However, we would like to emphasize that our novelty focuses on\nintegrating regulation of isotropic shell growth kinetics with asymmetric-wettability-\ndirected assembly to form microscale dense and ordered QD films, which significantly\nenhance patterning device efficiency, enabling scalable heavy-metal-free displays.\n1. Novelty in the regulation of shell growth kinetics.\nAlthough alkylamines and DPP-Se have been reported in the literature, we\nemployed the specific combination of n-octylamine and DPP-Se and explicitly\nelucidated its role in the active control of homogeneous surface energy and\ncrystallization kinetics. This approach fundamentally differs from conventional\nmethods that rely on high-boiling-point amines such as trioctylamine (TOA) for purely\nthermodynamic control. Due to its large steric hindrance and weak coordination ability,\nTOA is primarily used to provide an inert environment rather than achieving precise\npassivation. In contrast, the smaller steric hindrance and stronger coordination ability\nof n-octylamine, in synergy with the rapid selenium release from DPP-Se, enable\nkinetic control over ZnSe shell growth. This approach significantly improves the shell\nuniformity and enhanced passivation of defect states at the InP/ZnSe interface. This\nstrategy of achieving controllable synthesis of quasi-spherical InP quantum dots (QDs)\nby modulating surface energy represents a novel method developed based on\nconventional routes.\n2. Towards scalable heavy-metal-free displays: a pathway to overcoming high-\nresolution QLED efficiency challenges.\nA key factor limiting patterning efficiency in high-resolution QLEDs is the\nformation of non-uniform and porous QD films, which lead to pixel crosstalk, defects,\nand current leakage (J. Am. Chem. Soc. 140, 8690-8695 (2018)). This issue is\nparticularly severe with morphologically imperfect InP-based QDs. Our work addresses\nthis challenge by combining the highly symmetric QDs with an asymmetric-wettability-\nmediated assembly strategy. This approach precisely controls solvent evaporation and\nguides the directional dewetting of the three-phase contact line, thereby suppressing the\nchaotic flows and enabling the formation of orderly packed, dense, and precisely\npatterned QD films at the microscale. Consequently, these devices achieve remarkable\nefficiency (average EQE ≈20%) even at ultrasmall pixel sizes of 1.5-20 μm.\nFurthermore, the strategy is compatible with current industrial standard processes,\nenabling the fabrication of active-matrix QLED display devices. It provides scalable\nsolutions for heavy-metal-free QD display technology, a feature rarely demonstrated in\nprevious works.\nIn summary, we believe this work achieves significant breakthroughs in multiple\naspects, including innovation in the mechanism of the synthetic strategy, realization of\nquasi-spherical QDs, self-assembly patterning techniques, high-efficiency patterned\nQLEDs, and active-matrix display demonstrations.These achievements fully meet the\ncriteria of novelty and impact required by Nature Communications. We hope these\nclarifications adequately address Reviewer 1's concerns regarding the novelty of our\nstudy.\nComment 2: The authors demonstrated that using octylamine:DPP-Se, they eliminated\nthe facet-selective growth; however, there is a rich literature available where\noctylamines in combination with TOP-Se have shown the growth of homogenous ZnSe\nshells on InP QDs, affecting the novelty of this work. For example consider the\nrepresentative works below: [1] Nature575, 634–638 (2019); [2] Nature635, 854–859\n(2024).\nResponse to comment 2: We sincerely appreciate the reviewer for providing insightful\ncomments and highlighting these highly relevant references (Nature 575, 634–638\n(2019); Nature635, 854–859 (2024)). These studies have made indelible contributions\nto the development of the InP-based QDs and also serve as important references for the\nhomogeneous shell growth of InP-based QDs. However, we would also like to clarify\nthe distinctions of our work.\n1. Superior morphological and assembly control - comparison of experimental\nresults highlighting novelty.\nCompared with the TEM images of InP-based QDs synthesized with trioctylamine\n(Nature 575, 634–638 (2019); Nature 635, 854–859 (2024)), the InP/ZnSe/ZnS QDs\nobtained in this study exhibit a more uniform particle size distribution and higher\nroundness, thus achieving a higher degree of ordered assembly (Fig. R1). Such\nenhanced morphological control and ordering are critical for achieving efficient self-\nassembly and improving the performance of display devices (Nat Commun 16, 4257\n(2025);Nat Commun16, 7643 (2025)).\n2. Mechanistic distinctions supported by theoretical calculations.\nThrough binding energy calculations (Fig. R1), we confirmed that n-octylamine\nexhibits a significantly higher binding energy to the QD surface compared to\noleylamine and TOA, which is closely associated with its smaller steric hindrance and\nstronger coordination capability. The rapid selenium release kinetics of DPP-Se, in\nsynergy with n-octylamine, substantially altering the energy landscape of the core\nsurface during the early stages of shell growth, thereby effectively eliminating facet-\nselective growth.\n3. Distinct core mechanism from conventional thermodynamic control in the\nliterature.\nIn previous studies, the combination of alkylamines (particularly TOA) and TOP-\nSe primarily facilitated shell growth through thermodynamic control in a high-boiling-\npoint environment. Owing to its substantial steric hindrance and weak coordination\nability, TOA exhibits limited effectiveness in passivating small facets. In contrast, our\nstudy employs a specific combination of n-octylamine and DPP-Se, and explicitly\ndemonstrates its role in kinetic regulation and targeted facet passivation. This approach\nrepresents not merely a solvent or ligand substitution, but a novel mechanism enabling\nisotropic growth through precise surface energy modulation.\nTherefore, our work presents a rational ligand engineering strategy that distinctly\ndiffers from conventional thermodynamic approaches, enabling precise kinetic control\nover shell morphology.\n[FIGURE REDACTED]\nFig. R1.a, TEM images of green InP/ZnSe/ZnS QDs (Nature635, 854–859 (2024)). b,\nSTEM images of red InP/ZnSe/ZnS QDs (Nature 575, 634–638 (2019)). c, TEM\nimages of InP/ZnSe/ZnS QDs in this work.\nFig. R2. Adsorption model and the binding energy (ΔE) of a, tri-octylamine, b,\noleylamine and c, n-octylamine on (111) facet of InP.\nComment 3: In the XRD analysis (Fig. 1h), the authors claimed that the reduced (111)\npeak intensity in SEC QDs shows suppressed ZnSe growth on the (111) facet. However,\nthe XRD peak intensities are also influenced by multiple factors, including crystal\norientation, size effects, etc.\nResponse to comment 3: We sincerely appreciate the reviewer’s constructive feedback.\nThe use of XRD as an auxiliary method for identifying facet-selective growth has been\nwidely validated in numerous studies (e.g., Angew. Chem. Int. Ed.59, 5385 (2020); Nat\nCommun. 15, 5484 (2024)). Moreover, we did not rely solely on the reduction in the\n(111) peak intensity as independent evidence; instead, we combine it with EDS\nmapping and TEM images, as shown in Supplementary Fig. 5 and Figs. R3 and 4.\nWhile WEC QDs exhibit (111) facet-preferential growth leading to a tetrapod-like\nmorphology, the SEC QDs display a uniform spherical shape with multiple exposed\nfacets. The cross-validation of these multiple results supports our conclusion that the\nreduced (111) peak intensity in SEC QDs originates from suppressed growth of ZnSe\non the (111) facet.\nFig. R3.Morphology of QDs synthesized with the combination of OA and TOP-Se.\na, A high-angle annular dark field (HAADF) image. b, Energy dispersive spectroscopy\n(EDS) elemental mapping of Se elements from several WEC InP/ZnSe/ZnS QDs. c,\nEnergy dispersive spectroscopy (EDS) elemental mapping of Se (green), Zn (blue) and\nS (red) elements from several WEC InP/ZnSe/ZnS QDs. All the scale bars are equal to\n5 nm.\nFig. R4.RTEM images and inverse Fourier transform images of QDs synthesized\nwith the combination of (a) OA and TOP-Se and (b) n-octylamine and DPP-Se.The\nscale bars in the HRTEM images and the FFT images are 5 nm and 1 nm, respectively.\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 6, Lines 16-27: Energy-dispersive spectroscopy element mapping demonstrates\nthe distribution of Se in QDs synthesized with OA and TOP-Se closely aligns with the\npod-like morphology, demonstrating more pronounced facet-selective growth as the\nZnSe shell thickens (Supplementary Fig. 6)32,33. In contrast, the InP/ZnSe/ZnS QDs\nsynthesized using n-octylamine with DPP-Se possess a highly symmetric\ncore/multishell structure with uniform ZnSe shell growth (Supplementary Fig. 7). In\naddition, X-ray diffraction in Fig. 1h also shows that the (111) facet diffraction peak\nintensity of InP/ZnSe/ZnS QDs synthesized with a combination of n-octylamine and\nDPP-Se ligands is the lowest, which is consistent with the high-resolution TEM images\nanalysis (Supplementary Fig. 8). These observations collectively indicate that our\nligand combination successfully suppresses the selective growth of ZnSe on the (111)\nfacet32.\nComment 4: While Figures 2f-h demonstrate superior photostability of SEC QDs\nthrough PLQY decay under UV irradiation, solution-phase PL intensity, and\ntemperature-dependent PL spectra, the authors provided no mechanistic explanation\nlinking these observations to enhanced electron confinement.\nResponse to comment 4: We sincerely thank the reviewer for this insightful and\nconstructive comment. We agree that clarifying the mechanistic link is essential. The\nenhanced electronic confinement achieves the superior photostability of SEC QDs\nthrough the following pathways:\n1. The enhanced electron confinement alleviating the surface defect recombination.\nThe uniform shell growth of SEC QDs significantly suppressed the delocalization\nof electron wavefunctions toward the shell surface. This effectively reduced PL\nquenching and exciton-surface coupling caused by electrons being captured by surface\ntraps (Adv. Funct. Mater. 30, 2005303 (2020); Angew. Chem. Int. Ed. 64, e202420421\n(2025)). The higher potential barrier for electrons to escape makes it more difficult for\nthe energy provided by ultraviolet light or temperature to drive electrons to the surface,\nsignificantly enhancing the stability.\n2. Enhanced electron confinement increases the exciton binding energy and boosts\nradiative recombination.\nThe effective confinement of electrons maximizes the spatial overlap between\nelectron and hole wavefunctions. Consequently, the Coulombic interaction between the\nelectron-hole pair is significantly enhanced, leading to an increase in the exciton\nbinding energy, making the exciton more stable against dissociation (Angew. Chem. Int.\nEd. 63, e202318777 (2024)). As a result, a higher fraction of photogenerated excitons\nin SEC QDs preferentially recombine radiatively, thereby directly manifesting as the\nstronger PL intensity and superior stability observed under various harsh conditions.\nTo enhance the quality of our manuscript, we have revised relevant discussions in\nthe manuscript, as detailed below:\nPage 8, Lines 2-13: Additionally, the SEC QDs achieved a PLQY of 92.28%,\nsignificantly surpassing the 64.46% of the WEC QDs, and exhibited superior\nphotostability under UV irradiation (Fig. 2f and Supplementary Table 3). This enhanced\nperformance is attributed to the superior electron confinement, which effectively\nisolates electrons from surface traps and thereby significantly reducing non-radiative\nrecombination via exciton-surface coupling40,41. Concurrently, this confinement\npromotes greater overlap of electron and hole wavefunctions, which enhances the\nexciton binding energy and boosts the radiative recombination rate. This dual\nmechanism—promoting radiative recombination while suppressing non-radiative\ndecay—is further corroborated by the higher PL intensity of the SEC QDs at an\nequivalent optical density (Fig. 2g) and their exceptional stability in temperature-\ndependent PL measurements (Fig. 2h and Supplementary Fig. 12).\nComment 5: Regarding the device performance, the authors attributed 107.5-fold\noperational lifetime enhancement in SEC QD device exclusively to suppressed electron\nleakage into the HTL via strong electron confinement lacks mechanistic validation.\nThere could be other parameters involved, such as different ligands that could passivate\nthe QDs' surface and affect their overall stability under electric field.\nResponse to comment 5: We thank the reviewer for this constructive feedback. We\nagree that device operational stability is influenced by multiple factors. However, in\nour work, we propose that the primary factor contributing to the significant\nenhancement of device lifetime is the suppressed electron leakage achieved via stronger\nelectron confinement. It must be admitted that we did introduce new ligands when\nsynthesizing SEC QDs. To address the reviewer’s concern, we synthesized\nInP/ZnSe/ZnS QDs with a thinner ZnSe shell (~1 nm) compared to the SEC QDs (~2\nnm) also using n-octylamine and DPP-Se. We further fabricated devices based on these\nQDs and characterized their operational lifetime. The results show that the lifetime of\nthis QD-based device is only T ≈ 3457 h at 100 cd m-2, exhibiting merely a 6.3-fold\n50\nenhancement relative to the WEC QDs. Although these QDs share the same ligands as\nthe SEC QDs, the thinner ZnSe shell fails to achieve strong electron confinement (ACS\nEnergy Letters, 5 (4), 1316-1327), which still leads to electron leakage and poor device\nlifetime. This result clearly indicates that while the ligands themselves contribute to\nsome extent, the key factor responsible for the 107.5-fold enhancement in device\nlifetime is the strong electron confinement.\nFig. R5. Lifetime measurements of QLED devices based on InP/ZnSe/ZnS QDs\nsynthesized using n-octylamine and DPP-Se with a thinner ZnSe shell (~1 nm). a,\nLuminance and time dependency characteristics curves of devices based on\nInP/ZnSe/ZnS QDs synthesized using n-octylamine and DPP-Se with a thinner ZnSe\nshell (~1 nm). b, Extrapolation of accelerating factor (n) for the lifetime estimation.\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 11, Lines 12-19:To further rule out potential interference from different ligands,\nwe synthesized InP/ZnSe/ZnS QDs featuring a thinner ZnSe shell (~1 nm) compared\nto that of the SEC QDs (~2 nm), while maintaining the same ligands of n-octylamine\nand DPP-Se. The corresponding devices exhibited a lifetime of only T ≈ 3457 h at\n50\n100 cd m-2 (Supplementary Fig. 23), which mainly attributed to the insufficient electron\nconfinement of the thinner ZnSe shell. The result further confirmed that strong electron\nconfinement is the key factor underlying the significant improvement in device lifetime.\nComment 6: The authors provided no experimental evidence demonstrating how\nelectron leakage initiates HTL degradation, nor did they consider factors like interfacial\ndefect generation across different layers.\nResponse to comment 6: We sincerely thank the reviewer for this valuable comment.\nTo address this comment, we fabricated QLEDs with identical structures using two\ntypes of QDs and operated them at a constant current density of 2.0 mA cm-2 for 20 h.\nSubsequently, the top layers were carefully removed in a nitrogen-filled glovebox to\nexpose the PF8Cz layer (Nat. Commun. 14, 7785 (2023)). The results revealed that in\ndevices based on WEC QDs, the PF8Cz absorption exhibited a red shift with a\npronounced decrease in intensity, accompanied by enhanced low-energy emission,\nwhereas in devices based on SEC QDs, no significant changes in PF8Cz were observed\n(Fig. R6b-d). To confirm the origin of the significant degradation, we conducted XPS\nmeasurements on the aged HTL, the results showed that the O 1s spectrum of HTL in\nthe device based on WEC QDs presented an additional peak assigned to C=O at\n288.1eV, while this did not occur in the corresponding device based on SEC QDs (Fig.\nR6e, f). This observation demonstrated the electro-oxidation of fluorene units in PF8Cz\nto fluorenone group induced by leakage electrons. The significantly enhanced green\nband emission in the emission spectrum of PF8Cz after electrical aging of the device\nbased on WEC QDs also proves this point (Fig. R6g). (Adv. Mater.36, 2309123 (2024);\nJ. Phys. Chem. Lett. 11, 4649 (2020)). The generation of fluorenone defects hindered\nhole transport, and their strong electron-withdrawing effect reduces the band gap,\ncorresponding to a redshift in the absorption spectrum.\nFig. R6. The degradation mechanism of the HTL. a, Schematics of exposing the\nsurfaces of PF8Cz in the QLEDs by removing all the top layers. b, c, Absorption spectra\nof PF8Cz HTLs in QLEDs based on (b) WEC QDs and (c) SEC QDs before and after\noperation at 2.0 mA cm–2 for 20 h. d, e, XPS spectraof PF8Cz HTLs in QLEDs based\non (d) WEC QDs and (e) SEC QDs after electrical aging at 2.0 mA cm–2 for 20 h. f, PL\nspectra of PF8Cz in QLEDs based on WEC QDs before and after operation at 2.0 mA\ncm–2 for 20 h. g, The mechanism of electron leakage initiating HTL degradation by the\ngenerating fluorenone defect sites in PF8Cz.\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 10, Lines 25-28, Page 11, Lines 1-12: We attributed the substantially improved\noperational lifetime to strong electron confinement of SEC QDs, which suppressed\nelectron leakage to HTL and mitigates HTL degradation. To confirm the impact of\ncharge leakage on HTL degradation, we fabricated QLEDs with identical structures\nusing two types of quantum dots and operated them at a constant current density of 2.0\nmA cm-2 for 20 h. The top layers were then removed to measure the absorption and\nphotoluminescence spectra of PF8Cz before and after device operation (Supplementary\nFig. 22a). The results reveal that after the same operational time, the absorption of\nPF8Cz in devices based on WEC QDs shows marked redshift and decrease in intensity,\naccompanied by a significantly enhancements in the lower-energy emissions\n(Supplementary Fig. 22b-d). The emergence of additional peak assigned to C=O at\n288.1 eV in C 1s demonstrated that this degradation can be attributed to the electro-\noxidation of fluorene units in PF8Cz to fluorenone group induced by leakage electrons\n(Supplementary Fig. 22e-g)43,47. In contrast, the HTL in devices based on SEC QDs\nshows no evident degradation, suggesting that enhanced electron confinement helps to\nmitigate HTL degradation, thereby improving the operational stability of the devices.\nPage 15, Lines 20-25: The peel-off experiments were carried out on unencapsulated\nQLEDs in a nitrogen-filled glovebox to expose the PF8Cz layer. The Al cathode was\nfirst detached using polyimide tape. Then, the ZnMgO layer was washed away by spin-\ncoating 30 µL of an acetic acid-ethanol solution (0.8% by volume) at 2000 rpm for 30\nseconds, followed by the same process using 30 µL of pure ethanol. The QD layer was\nremoved by spin-coating 30 µL n-octane at 2000 rpm for 30 seconds.\nComment 7: The attribution of the 430 nm parasitic peak in WEC device solely to\nelectron leakage-induced recombination in the HTL requires further investigations. To\nstrengthen this claim the EL spectra from PF8Cz-based control device will be helpful\nto verify whether its intrinsic emission aligns with the 430 nm feature.\nResponse to comment 7: We are sincerely grateful to the reviewer for this constructive\nfeedback. Following the reviewer’s suggestion, we fabricated a PF8Cz-based control\ndevice with the structure ITO/PEDOT:PSS/PF8Cz/ZnMgO/Al and systematically\ncharacterized its EL spectrum. Their emission spectra under different driving voltages\nare shown in Fig. R7a. The intrinsic emission of PF8Cz exhibits two peaks at 407 nm\nand 435 nm, align consistently with those from devices based on WEC QDs (Fig. R7b).\nThis agreement indicates that the parasitic emission indeed originates from electrons\nleaking through the QD layer into the PF8Cz layer, where radiative recombination\noccurs.\nFig. R7.HTL emission caused by highly delocalized electron leakage from the InP\nQD layer to the HTL, where they recombine with holes. a, EL spectrum of PF8Cz-\nbased control device (with a structure of ITO/PEDOT:PSS/PF8Cz/ZnMgO/Al). b, EL\nspectra of QLED based on WEC InP/ZnSe/ZnS QD films under different voltages.\n(Inset: magnified spectra marked by the rectangle showing parasitic emission).\nTo strengthen our manuscript, we have revised our manuscript as follows:\nPage 9, Lines 15-20: Due to the strong electron delocalization driven by the electric\nfield, the EL spectrum of the QLED based on WEC QD films showed a parasitic\nemission peak (see Fig. 3c and Supplementary Fig. 18a), which is consistent with the\nintrinsic EL spectrum of PF8Cz (Supplementary Fig. 18b). This is attributed to highly\ndelocalized electron leakage from the InP QD layer to the HTL, where they recombine\nwith holes in the HTL21,25.\nComment 8: The maximum EQE of the QLED reported is 23.50% which is lower than\nthe recent reported EQE (26.68%) for the green InP QLED, why? (Nature 635, 854–\n859 (2024))\nComment 10: The T at 100 cd m−2 for QLED based on SEC InP QDs reached 59,151\n50\nh only, whereas the recent best reported case for green InP QLED demonstrated a T\n95\nof 89,900 h under similar brightness conditions. (Nature635, 854–859 (2024))\nResponse to comment 8 and 10: We sincerely thank the reviewer for their insightful\ncomments. The remarkable work in Nature 635, 854–859 (2024) indeed offers a new\nparadigm and direction for research on InP-based QLEDs, marking a significant\nmilestone in the development of their performance. We would like to clarify, however,\nthat our work specifically addresses the issue of facet-selective growth of ZnSe shells\nby proposing a ligand engineering strategy that significantly enhances electron\nconfinement. This approach is consistent with the perspective presented in Nature635,\n854–859 (2024) that low efficiency of green InP-based QD-LEDs originates from the\nlow electron concentration. Although the peak EQE (23.5%) and operational stability\n(T @100 cd m-2 = 59,151 h) reported in our study do not surpass the record-setting\n50\nvalues, they still rank among the highest values reported to date. Furthermore, our work\ndemonstrates the integration of high device performance with high-resolution\npatterning capability. The successful application in active-matrix displays provides a\nscalable template for high-performance, heavy-metal-free patterned QLED devices.\nIn the revised manuscript, we have explicitly highlighted this contribution in the\nIntroduction (Page 3, Lines 14–17) and compared our results with the state-of-the-art\nperformance records in the literature to underscore the unique value and application\npotential of our work:\nPage 3, Lines 14-16: Recent studies have clearly demonstrated that the inferior\nperformance of green InP-based QLEDs is primarily due to insufficient electron\nconcentration, a key finding that deepens the understanding of green InP-based\nQLEDs10.\nComment 9: The FWHM of the EL spectrum increased to 43 nm, much broader than\nits PL spectrum, which is 35 nm. No attention is paid to this factor, like what caused\nsuch broadening, as it affects the color purity.\nResponse to comment 9: We sincerely thank the reviewer for raising this critical point.\nWe have compiled and analyzed the full width at half maximum (FWHM) of both PL\nand EL spectra from published studies on green InP-based QLEDs (Table R1). The\ndata indicate that significant spectral broadening (often exceeding 10 nm) commonly\noccurs from PL to EL. The observed broadening of the EL spectrum can be attributed\nto the electric field-induced Stark effect: under an applied electric field, insufficient\nconfinement leads to a spatial shift of the wave function toward the shell surface and\nenhanced coupling with trap states (Nat Rev Electr Eng 1, 412–425 (2024); Light Sci.\nAppl. 11, 162 (2022)). This issue is particularly pronounced in InP-based QDs due to\nthe smaller electron effective mass and weaker electronic confinement by the shell\ncompared to Cd-based QDs. In this context, although an 8 nm broadening is observed\nin our devices, it represents an improvement compared to both control devices and the\nmajority of values reported in the literature.\nTable R1. PL and EL FWHM of green InP-based QDs reported in the literature.\nBroadening\nPL FWHM EL FWHM\nQD structure of FWHM EQE (%) Ref.\n(nm) (nm)\n(nm)\nInP/ZnSe S /ZnS 35 45 10 15.2 1\n0.7 0.3\nInP/ZnSe/ZnS 36 46 10 13.8 2\nInP/ZnSe/ZnS/BDA 35 45 10 16.3 3\nInP/ZnSe/ZnS 40 50 10 6.2 4\nInP/ZnSe/ZnS 35 38-39 4 26.68 5\nInP/ZnS 43 48 5 6.75 6\nInP/Q-ZnSe/ZnS 36 44 8 10.6 7\nInP/ZnSeS/ZnS 36 42 6 5.56 8\nInP/ZnSeS/ZnS 45 55 10 7.06 9\nInP/ZnSe/ZnS 43 >50 17 15 10\nInP/ZnSe/ZnSe S\nx 1-\n39 ~50 11 15.4 11\n/ZnS\nx\nOur\nInP/ZnSe/ZnS 35 43 8 23.5\nwork\nReferences\n1. Yu, P. et al. Highly efficient green InP-based quantum dot light-emitting diodes\nregulated by inner alloyed shell component. Light Sci. Appl.11, 162 (2022).\n2. Wu, Q. et al. Bridging Chloride Anions Enables Efficient and Stable InP Green\nQuantum-Dot Light-Emitting Diodes. Adv. Optical Mater.11, 2300659(2023).\n3. Chao, WC. et al. High efficiency green InP quantum dot light-emitting diodes by\nbalancing electron and hole mobility. Commun. Mater.2, 96 (2021).\n4. Sun, Z. et al. Suppressing the Cation Exchange at the Core/Shell Interface of InP\nQuantum Dots by a Selenium Shielding Layer Enables Efficient Green Light-Emitting\nDiodes. ACS Appl. Mater. Interfaces14, 15401−15406 (2022).\n5. Bian, Y. et al. Efficient green InP-based QD-LED by controlling electron injection\nand leakage. Nature635, 854-859 (2024).\n6. Wang, L. et al. Modified Charge Injection in Green InP Quantum Dot Light-\nEmitting Diodes Utilizing a Plasma-Enhanced NiO Buffer Layer. J. Phys. Chem. C128,\n3985−3993 (2024).\n7. Wu, Q. et al. Quasi-Shell-Growth Strategy Achieves Stable and Efficient Green InP\nQuantum Dot Light-Emitting Diodes. Adv. Sci.9, 2200959 (2022).\n8. Zhao, H. One-Pot Synthesis of InP Multishell Quantum Dots for Narrow-\nBandwidth Light-Emitting Devices. ACS Appl. Nano Mater.6, 3797-3802 (2023).\n9. Liu, P. et al. Green InP/ZnSeS/ZnS Core Multi-Shelled Quantum Dots Synthesized\nwith Aminophosphine for Effective Display Applications. Adv. Funct. Mater. 31,\n2008453 (2021).\n10. Gao, P. et al. Efficient InP Green Quantum-Dot Light-Emitting Diodes Based on\nOrganic Electron Transport Layer. Adv. Opt. Mater. 10, 2202066 (2022).\n11. Luo, Y. et al. Suppression of Interfacial Oxidation in Core/Shell InP Quantum Dots\nthrough Solvent Assisted Core-Etching Strategy for Efficient Green Light-Emitting\nDiodes. Nano Lett.25, 593-599 (2025).\nResponse to Reviewer 2:\nComment 1: The authors report that the combined use of n-octylamine and DPP-Se\nenables isotropic ZnSe shell growth on InP cores, thereby enhancing electron\nconfinement. They achieve a QY above 92%, an FWHM as narrow as 35 nm, a QLED\nEQE exceeding 23.5%, and a maximum brightness above 140,000 cd m⁻². They also\ndemonstrate an asymmetric wettability-mediated assembly strategy for QD arrays with\na resolution of 8,460 ppi, integrated into an AM-display prototype.\nIt is known that ZnSe tends to exhibit facet selectivity, and the facet-selective growth\nonly has a limit for effective electron confinement as well. The authors claim that the\nuse of n-octylamine and DPP-Se homogenizes surface energy and suppresses the (111)\nfacet selectivity of ZnSe growth. While this approach is interesting, it should be noted\nthat n-octylamine and DPP-Se have been frequently employed in previous studies, and\nthe reported QY of 92% is not significantly higher than in prior literature. Similarly, the\nQLED EQE of 23.5% is not unprecedented, with the highest reported value for green\nInP devices reaching 26.7% (Ref. 10 in this manuscript). However, the reported average\npeak EQE of around 20% for AM-LED devices is, to the best of my knowledge,\nunprecedented and represents a noteworthy achievement.\nResponse to comment 1: We sincerely thank the reviewer 2 for the time and effort\ninvested in providing constructive feedback and for acknowledging the unprecedented\nachievement in our AM-LED devices. We would also like to clarify the distinctions and\ncontributions of our work.\n1. Distinct ligand combinations and mechanisms of shell growth regulation.\nIn previous studies on InP-based QDs (Nature 575, 634-638 (2019); Nature 635, 854-859(2024)), particularly trioctylamine (TOA) was commonly used among\nalkylamines, primarily leverages its high boiling point for thermodynamic control to\nfacilitate shell growth. Due to its large steric hindrance and weak coordination ability,\nTOA is primarily used to provide an inert environment rather than achieving precise\npassivation. In contrast, our work precisely utilizes the stronger binding and smaller\nsteric profile of n-octylamine, synergized with the rapid Se release kinetics of DPP-Se,\nto achieve kinetic control over shell growth. This strategy of achieving controllable\nsynthesis of quasi-spherical InP-based QDs by modulating surface energy represents a\nnovel method developed based on conventional routes.\n2. Overall innovation and application advancement.\nWhile the PLQY (92%) and peak EQE (23.5%) reported in our study do not surpass\nthe record values, they still rank among the highest values reported to date. Numerous\nestablished studies have demonstrated that a high PLQY, while beneficial, is not the\nsole determinant of high electroluminescence performance (Nat. Rev. Electr. Eng. 1,\n412–425 (2024)). Efficient charge injection and balanced transport are equally critical\n(Chem. Commun. 55, 3501–3504 (2019); Nano Lett. 21, 7252–7260 (2021)), which our\ndevices successfully achieve. Furthermore, not only have we made progress in\nsynthesizing high-performance InP QDs, but we have also employed an asymmetric\nwettability-mediated self-assembly strategy to achieve orderly and precise patterning\nof QDs at the micrometer scale, while preserving their excellent electroluminescent\nperformance (EQE > 20%). The strategy is compatible with current industrial standard\nprocesses, enabling the fabrication of active-matrix QLED display devices. It provides\nscalable solutions for heavy-metal-free QD display technology, a feature rarely\ndemonstrated in previous works.\nComment 2: The relationship between ZnSe shell thickness and electron confinement\nhas been quantitatively discussed in earlier reports (e.g., ACS Energy Letters, 5 (4),\n1316-1327). A more developed interpretation in comparison to those works would\nstrengthen the paper.\nResponse to comment 2: We sincerely thank the reviewer 2 for providing constructive\nfeedback. Prior literatures have provided useful guidance regarding the relationship\nbetween ZnSe shell thickness and electron confinement. For green-emitting InP cores,\nit has been suggested that a shell thickness of at least 1.47 nm is required to remains\n95% probability of electron below the ZnSe shell. However, such models are often\nsimply based on isotropic spherical morphology and do not take into account the\nirregular morphologies caused by the selective growth of ZnSe. In this case, inevitably,\na much thicker ZnSe shell is often required.\nIn contrast, our work achieves oriented ZnSe shell growth through surface energy\nmodulation, which enhances electron confinement even at a shell thickness of ~2 nm,\nwell within the range predicted by the referenced study (ACS Energy Letters, 5 (4),\n1316-1327). Unlike conventional strategies that rely primarily on increasing shell\nthickness, we introduce surface energy modulation as a new dimension for achieving\nstrong electron confinement in relatively thin shells. The resulting QDs, which combine\nisotropic morphology with strong electron confinement, are better suited for our\nassembly strategy. This enables the formation of more uniform and defect-free\npatterned films, ultimately leading to improved performance in high-resolution displays.\nWe thank you for recommending this literature, which have been included in our\nrevised manuscript. To strengthen our manuscript, we have included related discussion\nas:\nPage 3, Lines 24-25: However, ZnSe tends to show facet-selective growth on InP cores,\nwhich leads to stronger electron delocalization that deviates from the spherical ZnSe\nshell model16.\nPage 26, Lines 9-11: 16. Jang, E. et.al. Environmentally Friendly InP-Based Quantum\nDots for Efficient Wide Color Gamut Displays. ACS Energy Lett.5, 1316-1327 (2020).\nComment 3: In addition, evidence beyond lattice parameter analysis is needed to\nsupport the claim that facet selectivity governs ZnSe morphology development.\nResponse to comment 3: We sincerely thank you for this insightful comment. In the\nrevised manuscript, we have added energy-dispersive X-ray spectroscopy (EDS)\nelemental mapping of the tetrapod-shaped WEC QDs (Fig. R8). The distribution of Se\nclosely aligns with the pod-like morphology, demonstrating pronounced facet-selective\ngrowth. This result further supports the argument that morphological evolution of the\nZnSe shell is dominated by facet-selective growth.\nFig. R8.Morphology of QDs synthesized with the combination of OA and TOP-Se.\na, A high-angle annular dark field image. b, EDS mapping of Se elements. c, EDS\nmapping of Se (green), Zn (blue) and S (red) elements. All the scale bars are equal to 5\nnm.\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 6, Lines 16-22: Energy-dispersive spectroscopy element mapping demonstrates\nthe distribution of Se in QDs synthesized with OA and TOP-Se closely aligns with the\npod-like morphology, demonstrating more pronounced facet-selective growth as the\nZnSe shell thickens (Supplementary Fig. 6)32,33. In contrast, the InP/ZnSe/ZnS QDs\nsynthesized using n-octylamine with DPP-Se possess a highly symmetric\ncore/multishell structure with uniform ZnSe shell growth (Supplementary Fig. 7).\nComment 4: In the present study, the QDs have an approximate overall diameter of 7\nnm, with an InP core of ~2 nm and a ZnSe thickness of ~2 nm required for >95%\nelectron confinement, plus ~0.5 nm ZnS for further confinement. These dimensions\nsuggest a QD size near the minimal requirement. Considering that in Ref. 10 isotropic\nZnSe shells of 2.5 - 4.5 nm thickness (overall size 8 - 12 nm) were successfully\nsynthesized and used, and that this was a key improvement in that work, the shell\nthickness in the present study is actually smaller. Thus, it would be valuable for the\nauthors to further highlight what is truly new here compared to previous results.\nResponse to comment 4: We sincerely thank the reviewer for these insightful comments.\nWe respectfully emphasize that, the true novelty of our work lies not in maximizing\nshell thickness, but in achieving precise control over the shell morphology and interface\nquality at this critical, size-constrained regime. While Ref. 10 achieved impressive\nresults with larger QDs, they are not strictly isotropic and did not form long-range\nordered arrangements or more uniform emissions. Our work demonstrates that a\nrelatively thinner (~2 nm), ultra-uniform shell is sufficient to yield superior and\nconsistent optoelectronic performance enabled by strong electron confinement through\nprecise surface energy regulation from the earliest stages. In contrast to the thick-shell\nstrategies emphasized in previous studies, we have expanded the approach to achieving\nstrong electron confinement by introducing surface energy modulation in thin shells as\na novel dimension. In this case, a thicker ZnSe shell layer was no longer needed. A\nlarger size would instead lead to the accumulation of internal defects, resulting in a\ndecrease in fluorescence intensity (Adv. Energy Mater. 15, 2400148 (2025); J. Phys.\nChem. Lett. 6, 1559–1562 (2015); Nano Letters 3, 799–803 (2003)).\nComment 5: The reported PL and EL characteristics of the SEC and WEC QDs—PL:\n537 nm (35 nm) and 542 nm (42 nm), EL: 542 nm (43 nm) and 552 nm (52 nm),\nwith Stokes shifts of 5 nm and 10 nm (Supporting Fig. 14)—are indeed consistent with\nexciton delocalization effects in core/shell QDs, particularly those arising from the\nrelatively light electron. However, this outcome is predictable, and the novelty in this\ncontext should be clarified. For example, the SEC and WEC decay times differ by ~1.4\n×, and the current density difference in EOD devices is ~1.6×. Given that decay times\nare on the nanosecond scale while current measurements are much slower, it is not\nimmediately clear how these differences can be directly attributed to electron\nconfinement in the QDs. A more detailed explanation would help—for instance, could\nEL decay time be interpreted in relation to device current density, or could PL changes\nunder applied electric fields provide further insight? I encourage the authors to address\nsuch points in more detail.\nResponse to comment 5: We thank the reviewer for raising these insightful points. The\ncorrelation between nanosecond-scale PL lifetime and macroscopic current density\narises from their shared dependence on electron confinement. The extended PL lifetime\nobserved in SEC QDs (84.83 ns vs. 57.95 ns, a difference of approximately 1.4×) stems\nfrom reduced electron wavefunction leakage, which suppresses non-radiative\nrecombination pathways by minimizing interactions with defect states at the QD surface.\nIn contrast, WEC QDs exhibit weaker electron confinement, leading to enhanced non-\nradiative recombination through surface trap states. Although WEC QD-based devices\nshow a significantly higher current density (1.6×) in EOD compared to SEC-based\ndevices, their device efficiency is markedly lower. This reduction is similarly attributed\nto leakage currents resulting from insufficient electron confinement, which affects the\ncharge balance.\nFurthermore, we have supplemented electric-field-dependent PL measurements in\nthe revised manuscript. WEC QDs exhibit pronounced PL quenching (60 %) with a red\nshift of ~5 nm, showing a high sensitivity to the electric field owing to the field-induced\nelectron dissociation (Adv. Mater.36, 2309123 (2024)). In contrast, SEC QDs were less\nsensitive to electric fields and demonstrate minimal PL quenching (14 %) with a red\nshift of ~2 nm, indicating strong confinement.\nFig. R9.PL spectra under different applied electric fields of (a)WEC QDs and (b)\nSEC QDs in EOD (ITO/ZnMgO/QD/ZnMgO/Al).\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 9, Lines 7-15: The EL spectra of the SEC QDs exhibit a redshift of approximately\n5 nm compared to the PL spectra, whereas the EL spectra of the WEC QDs shows a 10\nnm redshift along with significant broadening (Supplementary Fig. 16). Furthermore,\nin electric-field-dependent PL measurements, the WEC QDs showed a higher\nsensitivity to the electric field and demonstrate more pronounced PL quenching and red\nshift with increasing voltage compared to the SEC QDs (Supplementary Fig. 17). These\nobservations indicate a weaker Stark effect in the SEC QDs under an electric field,\nwhich can be attributed to strong electron confinement that suppresses the\ndelocalization of electron wavefunctions toward the shell surface2,43.\nComment 6: The most importantly, the paper discusses tuning the InP core surface\nenergy to control ZnSe growth and includes DFT calculations. While this addresses the\nearliest stage of core-shell interface formation, experimental evidence suggests that the\ninitial ZnSe nucleation on InP surfaces tends to be relatively isotropic, even with the\nfacet selectivity. However, the final morphology (derived from the facet selectivity)\nemerges more strongly as the ZnSe layer thickens (not on the InP core surface). Thus,\nthe current interpretation may not fully capture the later stages of shell growth. It may\nbe worth considering additional mechanisms and evidence—for example, calculating\nsurface energies for ZnSe facets during shell growth as the shell evolves, or showing\npossible pathways by which lattice mismatch is accommodated as the shell evolves.\nThese are only suggestions, and better approaches can also be suggested by authors.\nResponse to comment 6: We sincerely thank the reviewer for this insightful and\nconstructive comment. In response to Reviewer 2’s valuable suggestions, we\nsupplemented the morphological evolution analysis of the ZnSe shell in the later stage\nof growth. The distribution of Se elements in the EDS element mapping of WEC QDs\nshows that without any surface modifiers, the anisotropic growth of ZnSe will indeed\nbecome more pronounced as the ZnSe shell thickens (Fig. R10). To better understand\nthe role of surface energy in the later stages of shell growth, we have now calculated\nthe surface energies of the (111), (100) and (110) facets of ZnSe as the shell evolves\n(Fig. R11 and Table R2). The results show that the (111) facet exhibits a significantly\nhigher surface energy compared to the (100) and (110) facets (Angew. Chem. Int. Ed.\n59, 5385 (2020); Nat. Commun.16, 2450 (2025)). But when n-octylamine and DPP-Se\nare adopted, they preferentially adsorb onto the ZnSe (111) facet and markedly reduce\nits surface energy. These results suggest that the ligands we adopted do not merely\ninfluence the initial shell growth on the InP core surface but continue to play a crucial\nrole throughout the entire ZnSe shell growth process. By dynamically stabilizing high-\nenergy facets, the ligands help balance growth rates across the three facets, resulting in\na more uniform QD morphology as the shell thickens.\nFig. R10. Morphology of QDs synthesized with the combination of OA and TOP-\nSe. a, A high-angle annular dark field (HAADF) image. b, Energy dispersive\nspectroscopy (EDS) elemental mapping of Se elements from several WEC\nInP/ZnSe/ZnS QDs. c, Energy dispersive spectroscopy (EDS) elemental mapping of Se\n(green), Zn (blue) and S (red) elements from several WEC InP/ZnSe/ZnS QDs. All the\nscale bars are equal to 5 nm.\nFig. R11. Slab model of QD facets with ZnSe epitaxial layer. Slab model for the\n(111), (100), and (110) facets of InP substrate with a monolayer ZnSe epitaxial layer\nwithout ligands (top) and with ligands (bottom).\nPost-adsorption surface Formation energy\nFacets surface energy (eV Å-2)\nenergy (eV Å-2) (eV)\n(111) 0.509 0.288 -51.19\n(100) 0.303 0.172 -17.57\n(110) 0.103 0.100 -0.52\nTable R2. DFT formation energies of octylamine and DPP-Se on (100), (110) and\n(111) facets of InP with ZnSe epitaxial layer.\nComment 7: The comparison of SEC and WEC QDs—both having relatively low QY\ndue to less effective surface passivation—and the use of their FWHM and decay time\ndifferences to argue for electron confinement effects is not entirely convincing.\nLikewise, the performance difference between the corresponding QLED devices may\nnot be sufficient as sole evidence. Clarifying how the observed effects can be\ndistinguished from exciton or hole confinement (and attributed specifically to electron\nconfinement) would strengthen the argument.\nResponse to comment 7: We sincerely thank the reviewer for this insightful and critical\ncomment. For InP/ZnSe QDs, the valence band offset is larger than the conduction band\noffset (Nat. Nanotechnol. 18, 993–999 (2023)), resulting in stronger hole confinement\nand relatively weaker electron confinement. Additionally, electrons have a lighter\neffective mass compared to holes, which have a heavier effective mass (Nat. Rev. Electr.\nEng. 1, 412–425 (2024); Nature 635, 854–859 (2024)). As a result, epitaxial shell\ngrowth significantly influences the confinement strength and wave function leakage of\nelectrons, while having minimal impact on the confinement and wave function behavior\nof holes. For instance, in the case of SEC QDs coated with a ZnSe shell, the VD value\nof the first excitonic absorption peak increases compared to that of the core, indicating\nimproved size uniformity and a sharper electronic density of states. This strongly\nsuggests that the isotropic shell growth provides a highly uniform confinement\nenvironment for electrons, effectively minimizing electron wave function leakage and\nenergy disorder caused by an irregular shell structure. These findings are fully\nconsistent with the observed prolonged carrier lifetime and spectral narrowing.\nFurthermore, in Fig. 3c, the EL spectra of WEC QDs showed a gradual increase in\nthe 400-450 nm region as the driving current was increased, proving that the increase\nin the number of leakage electrons, which more fully excite the fluorescence emission\nof TFB. The parasitic emission peak attributed to the recombination of leaked electrons\nwith holes in the HTL eliminated completely in SEC QDs-based devices, also providing\ncompelling evidence that electron leakage has been suppressed by improved electron\nconfinement.\nComment 8: Notably, the use of DPP-Se to control Se reactivity has been reported\nmultiple times (e.g., Evans et al., J. Am. Chem. Soc., 132, 10973-10975, 2010), and\nvarious alkylamines have also been widely employed (Front. Chem., 6, 2018,\ndoi:10.3389/fchem.2018.00567). A recent paper (Nature Communications, 16, 1945\n(2025)) reported that combining DPP-Se with oleylamine allowed size and shape\ncontrol of ZnTeSe QDs, yielding improved quality under conditions similar to those\nhere (though n-octylamine was not used). These prior results suggest that the ligand\ncombination in the present study is not entirely unprecedented, though the authors have\napplied it to produce high-quality materials. A clearer mechanistic explanation of how\nsurface energy was tuned in this work would be beneficial.\nResponse to comment 8: We sincerely thank the reviewer for this insightful\ncomment. Although the literatures such as J. Am. Chem. Soc., 132, 10973-10975, 2010,\netc. mentioned that DPP-Se can accelerate the reaction kinetics of Se, it cannot\novercome the difference in surface energy barriers across crystal facets. As for the\nrecent study (Nat. Commun. 16, 1945 (2025)), although DPP-Se and oleamine were\nused in the nucleation of both types of ZnSeTe QDs, the IPG QDs presented a cubic\nshape, while the control QDs showed an irregular shape. The shape control in that work\nwas achieved by introducing a graded-potential shell (ZnSe Te ) to alleviate lattice\n0.9 0.1\nstress, with no evidence of facet energy modulation being observed. In addition,\ncompared with the TEM images of InP-based QDs synthesized with trioctylamine or\noleylamine (Nature575, 634–638 (2019); Nature635, 854–859 (2024)), our QDs have\na more uniform particle size distribution and higher roundness, thus achieving highly\nordered arrangement (Fig. R12).\nThrough binding energy calculation, we confirmed that this is because the binding\nenergy of oleamine and trioctylamine is much lower compared to that of n-octyl amine\nligands (Fig. R13), which is due to the large steric hindrance hinders their contact with\nthe QD surface, making it ineffective for facet passivation. In contrast, our work\nprecisely utilizes smaller steric hindrance and stronger coordination ability of n-\noctylamine, synergized with the rapid Se release kinetics of DPP-Se, to achieve kinetic\ncontrol over shell growth. The synergistic effect of this combination, introduced at the\ncritical early stage of shelling, directly and strongly alters the core's surface energy\nlandscape. This results in QDs with pronounced spherical morphology and a higher\ndegree of ordered assembly, which are critical for achieving superior performance in\noptoelectronic and display applications. Therefore, our work represents a deliberate and\noptimized ligand selection strategy that builds upon and advances previous synthetic\nmethodologies.\n[FIGURE REDACTED]\nFig. R12.a, TEM images of green InP/ZnSe/ZnS QDs (Nature635, 854–859 (2024)).\nb, STEM images of red InP/ZnSe/ZnS QDs (Nature 575, 634–638 (2019)). c, TEM\nimages of InP/ZnSe/ZnS QDs in this work.\nFig. R13. Adsorption model and the binding energy (ΔE) of a, tri-octylamine,\nb, oleylamine and c, n-octylamine on (111) facet of InP.\nComment 9: In conclusion, while the manuscript presents high-quality materials and\nstrong device results, the novelty of the synthesis approach and the proposed underlying\nmechanism are not yet fully convincing. I believe the work could be publishable in\nanother journal in its current form, but for Nature Communications, additional\nexperimental evidence and mechanistic justification would be necessary to clearly\nestablish the claimed novelty.\nResponse to comment 9: We sincerely thank the reviewer for their positive assessment\nof our materials and device performance. We understand and acknowledge your\nconcerns about establishing the mechanistic novelty.\nIn response to this comment, we have provided a more rigorous theoretical and\nexperimental foundation for the ligand-directed isotropic growth mechanism. New\nmultistage DFT calculations and TEM characterization track the evolution of surface\nenergies and morphology evolution throughout the synthesis, confirming the critical\nrole of our specific ligand combination (DPP-Se and n-octylamine) in maintaining\nisotropic growth by minimizing energy differences between different facets. These\ncombined computational and experimental results now provide a comprehensive\nmechanistic framework that not only explains how our synthesis strategy achieves\nuniform core-shell structures but also establishes its novelty compared to conventional\napproaches.\nWe believe that with this major revision, the manuscript will better meet the high\nstandards of Nature Communications.\nResponse to Reviewer 3:\nComment 1: Guo et al. have synthesized strongly electron-confined green InP QDs\ntowards heavy-metal-free ultrahigh-resolution active-matrix displays. They effectively\nsuppress selective growth of shell on the InP (111) facet through introducing n-\noctylamine and DPP-Se ligands. High-performing QLEDs based on these QDs exhibit\na peak EQE of 23.5%, a high luminance and long operational lifetime. Impressively,\nthe high-resolution QLEDs achieve a compelling 8,460 PPI resolution while\nmaintaining average peak EQEs comparable to thin-film QLEDs. I think this article is\ninteresting and meaningful for the next-generation eco-friendly displays based on\nheavy-metal-free QDs. I recommend publication after the following issues are\naddressed.\nResponse to comment 1: We sincerely thank the Reviewer 3 for the positive evaluation\nand encouraging comments regarding our work. We are very pleased that the reviewer\nrecognized the innovation and significance of our strategy for synthesizing strongly\nelectron-confined green InP QDs towards heavy-metal-free ultrahigh-resolution active-\nmatrix displays. As noted, the maintaining of high EQE and operational lifetime in\nmicroscale patterned QLEDs with a resolution density up to 8,460 PPI demonstrates\nthe potential of this method to address critical challenges in patterned QLEDsand have\non advancing impact on next-generation QD displays. Following the Reviewer 3's\nsuggestions, we have carefully revised the manuscript to address the remaining issues,\nas detailed below.\nComment 2: In this article, the authors mainly focus on the facet-selective growth of\nshell layers during the synthesis of InP-based QDs. They proposed that the synergistic\neffect of octylamine and DPP-Se ligands promotes uniform ZnSe shell growth, thereby\neffectively passivating surface defects. Although it is supported by morphological and\nspectroscopic data of InP/ZnSe/ZnS QDs, this article still lacks direct evidence for\nligand-mediated ZnSe uniformity without additional ZnS shell. It is essential to provide\ncomprehensive characterizations of InP/ZnSe QDs with different ligands (e.g. TEM\nimage, PLQY data, etc.) for the validation of their mechanism.\nResponse to comment 2: We thank the reviewer 3 for raising this constructive\nsuggestion. To address this, we have supplemented the manuscript with TEM images\nand PLQY data of InP/ZnSe QDs synthesized with different ligands (Fig. R14),\nthereby providing a more intuitive visualization of the influence of ligands on the\nuniform growth of the ZnSe shell. The results show that the ligands of n-octylamine can DPP-\nSe best optimize the morphology of the ZnSe shell, thereby achieving a much higher\nPLQY.\nFig. R14.The TEM images and PLQY of InP/ZnSe QDs with different ligands.\nTo enhance the quality of our manuscript, we have revised relevant discussions in\nthe revised version, as detailed below:\nPage 7, Lines 4-7: During the synthesis process, the InP/ZnSe QDs synthesized using\nthe combination of n-octylamine and DPP-Se exhibit higher PLQY (Supplementary\nFigs. 10 and 11a) and a significantly higher V/D value of 0.59 compared to 0.22 for that\nsynthesized with OA and TOP-Se (Fig. 2a), indicating a more effective and uniform\ngrowth of ZnSe.\nComment 3: Moreover, in Supp. Fig. 7, FTIR and XPS data can only demonstrate the\nexistence of octylamine, thus the authors need to add more data to verify the\ninvolvement of DPP ligands.\nResponse to comment 3: We thank the reviewer 3 for raising this constructive\nsuggestion. To characterize the successful coordination of the DPP ligand, we have\nsupplemented the manuscript with Fourier-transform infrared (FTIR) spectroscopy data\nof WEC and SEC QDs (Fig. R15). New characteristic peaks have emerged in the\ninfrared spectra of SEC QDs. The peaks at 750 cm-1 and 694 cm-1 are characteristic of\nthe C-H bending vibrations of monosubstituted benzene rings, while the bands at 1133\ncm-1, 1088 cm-1, and 1043 cm-1 correspond to the stretching vibrations of P-Ph bonds.\nThese characteristic signals provide strong evidence supporting the successful\nincorporation of DPP.\nFig. R15. Fourier-transform infrared spectra of WEC and SEC QDs.\nTo enhance the quality of our manuscript, we have revised our manuscript as\nfollows and supplemented related data:\nPage 6, Lines 27-28, Page 7, Lines 1-2: Fourier-transform infrared spectra and X-ray\nphotoelectron spectroscopy (XPS) of N 1s and In 3d confirmed that DPP and n-\noctylamine are successfully introduced and coordinated on the surface of the QDs\n(Supplementary Fig. 9).\nComment 4: More data or discussions are also needed to further evaluate the effect of\noctylamine and DPP-Se ligands on controlling facet-selective growth of InP/ZnSe QDs,\nexcept XRD and distribution statistics of QD size.\nResponse to comment 4: To further evaluate the effects of ligands on controlling the\nfacet-selective growth of InP/ZnSe QDs, in addition to XRD and QD size distribution\nstatistics, we defined the degree of isotropic shape through transmission electron\nmicroscopy images using a new parameter of circularity (c) (ACS Energy Letters, 5,\n1316-1327 (2020)). c is the degree of similarity of the shape to a perfect circle and is\ncalculated as . When the ZnSe shell is grown with\nligands of n-octylamine + DPP-Se, the QDs s2how a uniform and isotropic shape with c\n𝑐 = 4𝜋(𝑎𝑟𝑒𝑎)/(𝑝𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟)\n= 0.85, much higher than other ligands (c = 0.65 and c =0.77) (Fig. R16). This proves\nthe role of our ligands in promoting the isotropic growth of QDs.\nFig. R16. STEM images and corresponding circularity (c) distributions of the\nInP/ZnSe/ZnS QDs grown with (a, d) OA + TOP-Se, (b, e) n-octylamine + TOP-Se and\n(c, f) n-octylamine + DPP-Se.\nComment 5: It is particularly impressive that the SEC QD-based devices demonstrate\nsustained efficiency exceeding 20% across an extensive pixel size range (1.5-20 μm).\nFor the high performance in high-resolution devices, the authors attributed it to the\ncontrolled assembly achieved through their strategy besides the inherent properties of\nSEC QDs. They need to provide more detailed discussions to clarify the necessity of\ntheir assembly strategy.\nResponse to comment 5: We sincerely thank the reviewer for this positive feedback and\nfor recognizing the significance of our device performance across a wide range of pixel\nsizes. We also appreciate the valuable suggestion to provide a more detailed discussion\nelucidating the necessity of our assembly strategy. While the inherent high quality of\nthe SEC QDs is the fundamental basis for high performance, our controlled assembly\nstrategy is indeed the critical enabler for maintaining this high efficiency, especially in\nsub-20 µm pixels.\nFor comparison, we also fabricated a QD array via spin-coating. Confocal microscopy\nimages of this control sample (Fig. R17) reveal pronounced coffee-ring effects and\ninevitable pixel crosstalk, leading to a significant performance roll-off with decreasing\npixel size. In contrast, our asymmetric wettability-mediated assembly strategy enables\na slower and more controllable solvent evaporation rate, along with directed dewetting\nof the three-phase contact line (Nat Commun.16, 4257 (2025);Adv. Mater.34, 2110695\n(2022)). This effectively suppresses the chaotic fluid flow and coffee-ring formation\ntypically induced by rapid evaporation during spin-coating, resulting in the uniform and\ndense QD film (Fig. 4b and Supplementary Fig. 27). This uniform QD film improves\ncharge balance and radiation recombination, suppresses electron leakage, and therefore\nallows for high efficiency even when the pixel size decreases (Nat Commun. 16, 7643\n(2025)).\nFig. R17.Fluorescence micrograph of spin-coated micro-LEDs based on SEC QDs.\nScale bar: 20 µm.\nTo enhance the quality of our manuscript, we have added relevant discussions in\nthe revised version, as detailed below:\nPage 12, Lines 11-14: This maintained high performance with decreasing pixel size is\nattributed to controllable solvent evaporation and directed dewetting in our assembly\nstrategy, which effectively suppresses the pronounced coffee-ring effect and inevitable\npixel crosstalk in spin-coating (Supplementary Fig. 30)9,19.\nComment 6: In Supp. Fig. 15, the authors reported the carrier mobility of their core-\nshell QDs through hole-only/electron-only devices, which exhibit different device\nstructures of QLED device in Fig. 3a. To ensure reproducibility of this article, they need\nto provide the detailed methodology in both fabrication and measurement of these\ndevices.\nResponse to comment 6: We sincerely thank Reviewer 5 for raising this critical point.\nWe further elaborated the fabrication and measurement processes of hole-only and\nelectron-only devices in the Experimental section of Supplementary information. The\nspecific revisions are as follows:\nFabrication of HODs. PEDOT:PSS was spin-coated onto ITO substrates at 4000 rpm\nfor 40 s, followed by annealing at 150 °C for 30 min. Then, these substrates were\ntransferred into a nitrogen-filled glove box for spin-coating. PF8Cz with a\nconcentration of 8 mg mL-1 (solvent: chlorobenzene) was spin-coating at 3,000 rpm for\n40 s, and then baked at 120 ℃ for 30 min. The QD layer was prepared by spin-coating\nQD solution (20 mg mL-1) at 2,000 rpm for 30 s and baked at 80 °C for 7 min. MoO\n3\n(with a thickness of 40 nm) and Al electrode (with a thickness of 100 nm) was\nsuccessively deposited by thermal evaporation under a degree of vacuum of ≈ 2.5×10−4\nPa. Ultimately, the devices were encapsulated using UV-curable epoxy resin and cover\nglass in a glove box.\nFabrication of EODs. ZnMgO nanoparticles solution (20 mg mL-1) was spun-coating at\n2,000 rpm for 30 s and baked at 60 °C for 30 min. Subsequently, QD layer was prepared\nby spin-coating QD solution (20 mg mL-1) at 2,000 rpm for 30 s and baked at 80 °C\nfor 7 min, followed by a second spin-coating of the ZnMgO layer in the same\nparameters as before. Then, Al electrode (with a thickness of 100 nm) was deposited\nby thermal evaporation under a degree of vacuum of ≈ 2.5×10−4 Pa. Ultimately, the\ndevices were encapsulated using UV-curable epoxy resin and cover glass in a glove\nbox.\nThe current density-voltage (J-V) curves of the HODs and EODs were measured using\na commercial system (XPQY-EQE-Adv, Guangzhou Xipu Optoelectronics\nTechnology Co., Ltd.) by applying DC voltage scans (0 – 8 V, step size 0.2 V). The\nelectron and hole mobilities of both devices were calculated by fitting the space-charge-\nlimited current (SCLC) region, assuming no trap states (see details of calculation in\nSupplementary Note 6).\nComment 7: Other minor issues should be corrected. For example, the yellow\nindicators in Fig. 1a are unclear and should be optimized; The color scale in Fig. 2h\nlacks axis labels; The axis ranges and color bars in Supplementary Figs. 5 and 11 should\nbe unified for better clarity; Unit formats in Supplementary Fig. 11 should be made\nconsistent with the main text; In the figure caption of Supp. Fig. 15, electron-only\ndevices (HODs) is misspelled.\nResponse to comment 7: We sincerely appreciate Reviewer 3 for his/her careful and\nthorough inspection. We made point-to-point modifications to these issues as following\nand correct them in the revised manuscript. We think that these revisions have\nsignificantly improved the overall quality of the manuscript.\nFig. R18. Schematic illustration and representative high-resolution TEM images for\ntwo types of InP/ZnSe QDs.\nTo improve our manuscript, we have replaced Figure 1a with the new schematic\ndiagram (Fig. R18) in the revised manuscript (Page 19).\nFig. R19. Temperature-dependent PL spectra of SEC InP/ZnSe/ZnS QDs.\nTo improve our manuscript, we have replaced Figure 2h with the new schematic\ndiagram (Fig. R19) in the revised manuscript (Page 21).\nFig. R20. Supplementary Fig. 5 | Morphological characterization of QDs\nsynthesized with three combinations of ligands.\nFig. R21.Surface roughness for two types of QD thin films.\nTo improve our manuscript, we have replaced Supplementary Fig. 5 and\nSupplementary Fig. 11 with the Fig. R20 and Fig. R21 in the revised Supplementary\nInformation (Page 14 and Page 22).\nPage 28, Lines 4-5: c, d, SCLC measurements of electron-only devices (EODs) based\non SEC and WEC QD films.\nResponse to Reviewers and Revised Details\nResponse to Reviewer 1:\nComment 1: The authors have thoroughly addressed all the previous concerns and\nrevised the manuscript accordingly. The novelty and significance of the work are now\nclearly highlighted. I have no further comments, and the manuscript seems suitable for\npublication in Nature Communications.\nResponse to Comment 1:\nWe thank the reviewer 1 very much for the positive feedback and their valuable\ncomments throughout the review process!\nResponse to Reviewer 2:\nComment 1: The authors claim that the combined use of n-octylamine and DPP enables\nreduced steric hindrance of alkyl chains, improved surface conduction, and ultimately\nthe formation of quantum dots with superior properties compared to those synthesized\nin a conventional tri-octylamine solvent. They further argue that these improvements\nare experimentally validated and mechanistically supported through surface-energy\ncalculations on both InP cores and ZnSe shell growth. In particular, the authors’ efforts\nto extend their surface-energy analysis to ZnSe shell formation—and to correlate this\nwith uniform shell growth—are technically sound and represent a commendable\nattempt to support the proposed mechanism.\nResponse to Comment 1:\nWe sincerely appreciate the positive and insightful comments on our manuscript from\nReviewer 2. We are especially grateful for the reviewer’s recognition of our\nsupplementary experimental verification and mechanical evidence of surface energy\nmodulation and uniform growth of ZnSe shells. The reviewer’s affirmation that this\napproach is “technically sound and represents a commendable attempt” is highly\nencouraging and validates the significance of this part of our study.\nComment 2: However, despite these strengths, important questions remain regarding\nthe broader impact and originality of the findings. Considering the claimed surface-\nenergy modulation induced by n-octylamine, it is still unclear how the resulting\nimprovements compare with (i) the shell-thickness regimes previously established in\nthe literature, (ii) the commonly reported size distributions of InP/ZnSe(ZnS) QDs,\nand (iii) the state-of-the-art efficiencies of green InP-based QLEDs. Ligand\nmodifications—whether applied before or after growth—are well-known strategies,\nand n-octylamine itself is already a reasonable choice within the established ligand\nlibrary. Thus, it is difficult to identify what fundamentally new concept is being\nintroduced here, especially since the authors’ own analysis attributes the strong\nconfinement primarily to uniform shell growth for improved size/shape distribution or\nany facet-selective growth route.\nResponse to Comment 2:\nWe sincerely thank the reviewer 2 for this constructive feedback. To address reviewer’s\nconcerns, we compared our SEC QDs with the green InP-based QDs in representative\nstudies in recent years:\n(i) Comparison with shell-thickness regimes: Prior literatures have provided useful\nguidance regarding the relationship between ZnSe shell thickness and electron\nconfinement. For green InP cores, it has been suggested that a shell thickness of at least\n1.47 nm is required to remains 95% probability of electron below the ZnSe shell. Our\nSEC QDs possess a shell thickness of ~2 nm, well within the range predicted by the\nreferenced study (ACS Energy Letters, 5 (4), 1316-1327). In addition, our surface-\nenergy modulation strategy does not seek to replace established shell-thickness control\nbut rather to achieve unprecedented uniformity and conformality of the ZnSe/ZnS shell\nat any given target thickness. This precise morphological control is critical for\nconsistent charge confinement and transport, directly translating to improved device\nperformance and stability.\n(ii) Comparison with size distributions: As shown in the Table R1, the size distribution\nuniformity of our QDs is the highest among the compared works. This superior\nmorphological control is further corroborated by the TEM images and circularity\nanalysis in our first-round response (Fig. R1). Such enhanced morphological control\nand ordering are critical for achieving efficient self-assembly and improving the\nperformance of display devices (Nat Commun16, 4257 (2025); Nat Commun 16, 7643\n(2025)).\n[FIGURE REDACTED]\nFig. R1.a, TEM images of green InP/ZnSe/ZnS QDs (Nature635, 854–859 (2024)). b,\nSTEM images of red InP/ZnSe/ZnS QDs (Nature 575, 634–638 (2019)). c, TEM\nimages of InP/ZnSe/ZnS QDs in this work.\n(iii) Comparison with state-of-the-art efficiencies: As shown in the Table R1, although\nthe peak EQE (23.5%) reported in our study do not surpass the record-setting values,\nit still ranks among the highest values reported to date. Crucially, the core originality and\nbroader impact of our work lie in the successful integration of two critical achievements:\n(i) the synthesis of QDs with superior morphological uniformity via our surface-energy\nmodulation, and (ii) the high device performance can be maintained even under the\nstringent requirements of pixel-level patterning. The successful application on an\nactive-matrix display provides a scalable template for high-performance, heavy-metal-\nfree, patterned QLED devices.\nTable R1. Comparison of size distributions and EQEs in this work with the\nrepresentative literature on green InP-based QDs.\nQD structure Size distributions EQE (%) Year Ref.\nInP/Q-ZnSe/ZnS 5.7 ± 0.8 nm 10.6 2022 1\nInP/ZnSe/ZnS -- 15 2022 2\nInP/ZnSe S /ZnS -- 15.2 2022 3\n0.7 0.3\nInP/ZnSe/ZnS/BDA 8.6 ± 1.2 nm 16.3 2021 4\nInP/ZnSe/ZnS -- 6.2 2022 5\nInP/ZnSe/ZnS 6.5 ± 0.2 nm 13.8 2023 6\nInP/ZnSeS/ZnS 6.31 ± 0.48 nm 5.56 2023 7\nInP/ZnSe/ZnS 8.0 ± 1.9 nm 26.68 2024 8\nInP/ZnS -- 6.75 2024 9\nInP/ZnSe/ZnS -- 12.74 2024 10\nInP/ZnSe/ZnSe S /ZnS -- 15.4 2025 11\nx 1-x\nInP/ZnSeS/ZnS 8.0 ± 0.82 nm 26.3 2025 12\nOur\nInP/ZnSe/ZnS 7.2 ± 0.3 nm 23.5\nwork\nReferences\n1. Wu, Q. et al. Quasi-Shell-Growth Strategy Achieves Stable and Efficient Green InP\nQuantum Dot Light-Emitting Diodes. Adv. Sci.9, 2200959 (2022).\n2. Gao, P. et al. Efficient InP Green Quantum-Dot Light-Emitting Diodes Based on\nOrganic Electron Transport Layer. Adv. Opt. Mater. 10, 2202066 (2022).\n3. Yu, P. et al. Highly efficient green InP-based quantum dot light-emitting diodes\nregulated by inner alloyed shell component. Light Sci. Appl.11, 162 (2022).\n4. Chao, WC. et al. High efficiency green InP quantum dot light-emitting diodes by\nbalancing electron and hole mobility. Commun. Mater.2, 96 (2021).\n5. Sun, Z. et al. Suppressing the Cation Exchange at the Core/Shell Interface of InP\nQuantum Dots by a Selenium Shielding Layer Enables Efficient Green Light-Emitting\nDiodes. ACS Appl. Mater. Interfaces14, 15401−15406 (2022).\n6. Wu, Q. et al. Bridging Chloride Anions Enables Efficient and Stable InP Green\nQuantum-Dot Light-Emitting Diodes. Adv. Optical Mater.11, 2300659(2023).\n7. Zhao, H. One-Pot Synthesis of InP Multishell Quantum Dots for Narrow-\nBandwidth Light-Emitting Devices. ACS Appl. Nano Mater.6, 3797-3802 (2023).\n8. Bian, Y. et al. Efficient green InP-based QD-LED by controlling electron injection\nand leakage. Nature635, 854-859 (2024).\n9. Wang, L. et al. Modified Charge Injection in Green InP Quantum Dot Light-\nEmitting Diodes Utilizing a Plasma-Enhanced NiO Buffer Layer. J. Phys. Chem. C128,\n3985−3993 (2024).\n10. Cheng, Y. et al. High-brightness green InP-based QLEDs enabled by in-situ\npassivating core surface with zinc myristate. Mater. Futur.3, 025201 (2024).\n11. Luo, Y. et al. Suppression of Interfacial Oxidation in Core/Shell InP Quantum Dots\nthrough Solvent Assisted Core-Etching Strategy for Efficient Green Light-Emitting\nDiodes. Nano Lett.25, 593-599 (2025).\n12. Yuan, C. et al. Dual-Mode Strain Relief via Zinc Acetate Enables High-Efficiency\nInP Quantum Dot Light-Emitting Diodes. Angew. Chem. Int. Ed. 64, e202509765\n(2025).\nComment 3: The authors also argue that the SEC-type QDs yield high performance in\nunit QD-LED device tests, but such values are comparable to those already reported\nand do not, on their own, constitute a major conceptual advance suitable for Nature\nCommunications. In contrast, the demonstration of good performance in large scale\nAM-LEDs—indeed unprecedented—could have been a more compelling point of\nnovelty. If the manuscript had focused more deeply on how the SEC QDs maintain their\nperformance during process scaling and pixelation (connection between QDs and large-\narea/scale LED performances), this could have significantly strengthened its impact.\nResponse to Comment 3:\nWe sincerely thank the reviewer for this insightful comment. To better address\nReviewer 2's concerns, we analyzing the electroluminescence uniformity of pixels\nacross a range of sizes under confocal microscopy, respectively. The EL mapping and\nEL intensity curves observed under confocal fluorescence microscopy (Fig. R2) show\nthat the green QLEDs of different pixel sizes all exhibit homogeneous emission and\noptical flatness, ensuring that the performance does not vary with the reduction of pixels.\nThis highly uniform assembly is achieved because, compared to conventional\ndeposition methods, our asymmetric wettability- mediated assembly strategy enables a\nslower and more controllable solvent evaporation rate, along with directed dewetting\nof the three-phase contact line (Nat Commun.16, 4257 (2025); Adv. Mater.34, 2110695\n(2022)). This effectively suppresses the chaotic fluid flow and coffee-ring formation\ntypically induced by rapid evaporation during spin-coating, resulting in the uniform and\ndense QD film(Supplementary Fig. 27). The AFM surface roughness characterization\nalso confirmed this (Fig. R3). As the pixel size decreased from 20 µm to 1.5 µm, the\npixel surface roughness R remained below 1 nm at all times. The uniform spherical\nq\nmorphology of SEC QDs and their well-ordered self-assembly enabled by this\ncontrolled assembly process collectively enables uniform electroluminescence across a\nhigh-resolution display panel.\nFig. R2. The EL mapping and EL intensity linecut of high-resolution QLEDs with\ndifferent pixel sizes under confocal microscopy. (a) 20-2 μm, (b) 10-2 μm, (c) 5-2 μm,\n(d) 3-2 μm, (e) 2-2 μm, (f) 1.5-1.5 μm. The former value represents the side length of\nthe pixel, and the latter value represents the distance between adjacent pixels. Scale bar,\n10 µm.\nFig. R3. Surface roughness of QD arrays for different pixel sizes. AFM image of QD\narrays with pixel sizes of (a) 20-2 μm, (b) 10-2 μm, (c) 5-2 μm, (d) 3-2 μm, (e) 2-2 μm,\n(f) 1.5-1.5 μm. The former value represents the side length of the pixel, and the latter\nvalue represents the distance between adjacent pixels. Scale bars, 1 µm (a-c), 200 nm\n(d and e)and 100 nm (f).\nTo enhance the quality of our manuscript, we have added relevant discussions in the\nrevised version, as detailed below:\nPage 12, Lines 21-23: The uniform spherical morphology of SEC QDs and their well-\nordered self-assembly enabled by this controlled assembly process collectively enables\nuniform electroluminescence across the high-resolution display panel (Supplementary\nFig. 31).\nComment 4: Overall, while the manuscript presents scientifically solid work with high-\nquality materials, strong understanding of the field, and impressive device metrics, the\nconnection between these results and a demonstrably new conceptual advance in AM-\nLED technology remains insufficiently clear. For these reasons, despite of the\nappreciation of autors’ efforts, I regret to conclude that the work does not meet the\nnovelty and impact threshold required for Nature Communications. I recommend\nconsidering submission to a more specialized journal where the strengths of the study\nwill be more appropriately recognized.\nResponse to Comment 4:\nWe sincerely thank the reviewer for the comprehensive evaluation and for\nacknowledging that our manuscript presents “scientifically solid work with high-\nquality materials, strong understanding of the field, and impressive device metrics” We\nfully understand the concern regarding the connection between our material results and\na demonstrably new conceptual advance in AM-LED technology. However, we\nrespectfully wish to clarify that the optimization of quantum dot raw materials and the\nrealization of high-performance AM-LEDs are inextricably linked. The strongly\nelectron-confined InP-based QDs provide a superior material foundation, offering the\nnecessary stability and optoelectronic properties that are prerequisites for high-\nresolution displays. Additionally, we further demonstrated that our assembly strategy\nensures assemble uniformity, enabling the retention of peak EQE and maximum\nbrightness even when pixel sizes are significantly reduced, directly addressing a major\nchallenge in the field where performance typically degrades with scaling.\nBased on these comprehensive revisions and the deepened analysis of the underlying\nmechanisms, we are confident that this work now fully meets the novelty and impact\nstandards required for publication in Nature Communications.\nResponse to Reviewer 3:\nComment 1: The revised manuscript has satisfactorily addressed all of my concerns. It\nis now suitable for publication in Nature Communications.\nResponse to Comment 1:\nWe thank the reviewer 3 very much for the positive feedback and their valuable\ncomments throughout the review process!"}]

Decision letter