Phosphine-mediated hydrogen bond and phosphorescence energy transfer for tunable chiroptical afterglow in stacked polymers

Domain: chemistry
Published: 2026-02-10
Editorial outcome: major_revision

Abstract
Polymer-doped chiral organic afterglow (COA) materials represent an emerging frontier in photonics, yet their development is constrained by weak hydrogen bond interactions and limited spectral diversity. Herein, a supramolecular engineering strategy utilizing phosphonic acid-derived directional hydrogen bond networks is proposed to construct COA materials. Leveraging the tetrahedral coordination geometry and dual proton-donor functionality of phosphonic acid derivatives, a robust three-dimensional hydrogen bond network is formed with polyvinyl alcohol, yielding blue afterglow emission with a lifetime of 3.05 s, a photoluminescence quantum yield of 33.3%, and enhanced thermal stability. Structural and computational analyses reveal that near-linear hydrogen bond geometry and orbital hybridization synergistically enhance the hydrogen bond strength while enabling chiral amplification by an interfacial chiral polylactic acid coating. Furthermore, through efficient phosphorescence energy transfer, multicolor COA emissions are achieved in stacked polymeric films, exhibiting dissymmetry factors up to 0.03 and afterglow emissions across the visible spectra, allowing the development of customizable encryption inks with spatiotemporal resolved chiroptical signatures for multiple applications. This work not only thoroughly investigates the modulation of hydrogen bonds on afterglow properties but also provides a fundamental understanding of non-covalent interactions in organic optoelectronics.

Introduction
Chiral organic afterglow (COA) materials have garnered significant attention in next-generation optoelectronics due to their unique integration of persistent luminescence with chiroptical activity1–7, enabling applications in anti-counterfeiting encryption8–11, chiroptical analysis12–14, and stereoscopic displays15,16. While crystal engineering and supramolecular self-assembly strategies have demonstrated potential in constructing COA systems through π–π stacking optimization and vibrational suppression17–20, these approaches face inherent limitations in spectral tunability and intricate synthesis procedures. Polymer-based host-guest doping systems emerge as a versatile alternative, where hydrogen bond networks can simultaneously immobilize emitters to suppress non-radiative decay and flexibly modulate chiral and emissive properties through host-guest interactions21–24. However, conventional COA materials predominantly rely on hydrogen bonds mediated by carboxyl25,26, boronic acid27–30, and/or hydroxyl groups31–33. These interactions, though effective, often suffer from limited strength, particularly under elevated temperatures, restricting their ability to support high-efficiency and long-lifetime afterglow34,35. Therefore, there is an urgent need to explore alternative hydrogen bond motifs that offer stronger intermolecular interactions to enhance COA performance.

Principally, critical to this paradigm is the precise engineering of hydrogen bond strength and geometry, which is directly governed by the electronegativity of hydrogen bond acceptor that can be modulated by the connected atoms (X) and linear spatial arrangement of hydrogen bond (Fig. 1a)36–38. Phosphoric acid derivatives bearing the tetrahedral coordination geometry and dual proton-donor functionality are promising candidates for developing hydrogen bond networks. Previous report has revealed that phosphate-mediated hydrogen bonds achieve near-linear alignment (θ ≈ 175°), combining three-dimensional networking capacity and binding energies exceeding 25 kJ mol−1 due to the orbital coupling and delocalization39–42, which may enable enhanced hydrogen bond strength for constructing COA materials with improved efficiency and lifetime. Guided by these principles, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) containing phosphate groups is selected as the luminescent anchoring molecule. The phosphate groups endow a directional and multi-dimensional hydrogen bond network with hydroxyls of polyvinyl alcohol (PVA), enabling the suppression of molecular vibration induced exciton quenching (Fig. 1b). The prepared film achieves a blue organic afterglow with a main emission peak at 444 nm, lifetime of 3.05 s, and photoluminescence quantum yield (PLQY) of 33.3%. More importantly, compared to the carboxylic acid engineered hydrogen bond counterpart, 2PACz-doped PVA films exhibit much enhanced thermal stability. Meanwhile, by spinning chiral polylactic acid (PLA) on 2PACz-doped PVA (2PACz@PVA) films, a universal method for constructing COA emission is achieved, showing a maximum dissymmetry factor (glum) of 0.03. By utilizing a Förster resonance energy transfer (FRET) process, green, yellow, and red chiral afterglow emissions are achieved (Fig. 1c) through doping various fluorescence emitters into 2PACz@PVA@PLA films, thus empowering versatile afterglow inks for coating and encryption applications. These results not only provide a deep understanding to modulate the hydrogen bond interactions but also propose a feasible method to develop advanced COA materials for various applications.

Results
Synthesis and characterization
Phosphonic acid modified carbazole derivatives, 2PACz and (4-(9H-carbazol-9-yl)butyl)phosphonic acid (4PACz), were synthesized in three steps with high yields, and their molecular structures were determined by 1H, 13C, 31P-nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (Supplementary Fig. 1 and Supplementary Figs. 3–22). Additionally, a control molecule, a carboxylic acid modified carbazole derivative, (2-(9H-carbazol-9-yl)ethyl) carboxylic acid (2CACz), was synthesized to demonstrate the better of phosphonic acid groups in constructing strong hydrogen bond networks (Supplementary Fig. 2 and Supplementary Figs. 23–28). The melting temperatures of 2PACz, 4PACz, and 2CACz are 240, 285, and 175 °C, respectively (Supplementary Fig. 29). Generally, 2PACz@PVA film was prepared by evaporating the mixture of 2PACz ethanol solution and PVA aqueous solution. Through regulating the concentrations of 2PACz ethanol solution, 2PACz@PVA films with different doping concentrations could be easily achieved. 4PACz@PVA and 2CACz@PVA films with different doping concentrations were prepared by the same method (Supplementary Fig. 30). Thermogravimetric analysis of the 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films shows no significant mass loss up to 200 °C (Supplementary Fig. 31), and no ethanol peaks are detected in the ¹H NMR spectrum of the 2PACz@PVA film (Supplementary Fig. 32). These results collectively exclude any influence of volatile solvents on the observed luminescence properties.

Photophysical properties investigation
2PACz shows characteristic absorption and fluorescence features of carbazole in tetrahydrofuran solution, with a maximum absorption peak at 290 nm and emission peaks at 350 and 370 nm (Supplementary Fig. 33). The steady-state photoluminescence (SSPL) and delayed PL spectra of 2PACz@PVA films with different doping concentrations (0.1–1.0 wt.%) exhibit main fluorescence and afterglow emission peaks at 370 and 444 nm, respectively (Fig. 2a and Supplementary Figs. 34 and 35). Intense blue afterglow emission can be captured by a commercial camera for 30 s (Supplementary Fig. 36). Among these films, 0.5 wt.% 2PACz@PVA film achieves the highest fluorescence intensity, PLQY of 33.3% as well as the most pronounced afterglow intensity and longest afterglow lifetime (τA, 3.05 s) (Fig. 2b, c and Supplementary Table 1). Consequently, 0.5 wt.% 2PACz@PVA film demonstrates the best figure of merit, defined as QFM = PLQY × τA (Fig. 2d and Supplementary Table 1). Excitation-delayed PL emission mapping spectra (Fig. 2e) highlight a fixed afterglow emission peak at 444 nm upon excitation with 220-350 nm UV light, which is further corroborated by the time-resolved emission spectra (TRES) (Fig. 2f). The low-temperature delayed PL spectra of 2PACz in methyl tetrahydrofuran solution (Supplementary Fig. 37) exhibit identical emission behavior to that of the 0.5 wt.% 2PACz@PVA film, underscoring the isolated emission nature of the doped film.

Afterglow mechanism analysis
To further investigate the afterglow properties of 2PACz@PVA, a series of control experiments was conducted, focusing on variations in the alkane chain length (4PACz) and the end groups (2CACz) of 2PACz. As shown in Fig. 3a and Supplementary Fig. 38a, the delayed PL emission peaks of 0.5 wt.% 4PACz and 0.5 wt.% 2CACz-doped PVA films are almost identical to that of 2PACz@PVA film. These results suggest that the modulation of alkane chain length and end groups has a limited impact on the triplet properties of the carbazole chromophore. Notably, 2PACz@PVA film exhibits enhanced afterglow intensities and lifetimes compared to those of 4PACz and 2CACz-doped PVA films. Specifically, the 0.5 wt.% 4PACz and 2CACz doped PVA films show lifetimes of 2.84 s and 2.65 s as well as PLQYs of 30.3% and 30.1% (Fig. 3b and Supplementary Fig. 38b). This enhanced performance can be attributed to the additional n-π* transition contribution by the oxygen atom in P=O in the frontier molecular orbital distributions of 2PACz (Supplementary Fig. 39), thus enabling a much larger spin-orbit coupling constant of T1-S0 of 2PACz than that of 4PACz and 2CACz (Supplementary Fig. 40). Therefore, the 2PACz@PVA film demonstrates a higher QFM, underscoring its more exceptional and efficient luminescent properties (Supplementary Fig. 41). The temperature-dependent PL intensity variations illustrate the thermal stabilities of PL spectra for 0.5 wt.% 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films, indicating the comparative quenching behavior of afterglow emission at elevated temperatures (Fig. 3c and Supplementary Fig. 42). Notably, with increasing temperatures, the 2PACz@PVA film retains slightly much higher intensities than the others, highlighting its much improved thermal stability. Furthermore, the doped films exhibit stable afterglow at various temperatures (77–343 K) (Supplementary Fig. 43). The afterglow remains constant over time at 25% relative humidity, whereas at 90% humidity, moisture disrupts the hydrogen bond network in the film. This leads to the enhanced molecular vibrations and triplet excitons quenching, which significantly reduces afterglow intensity (Supplementary Fig. 44). The prepared 2PACz@PVA, 4PACz@PVA, and 2CACz@PVA films only display typical powder X-ray diffraction (XRD) patterns at 19°, which is attributed to the crystallization of PVA (Supplementary Fig. 45)43,44. This is further supported by wide-angle X-ray scattering (WAXS) measurements, which show scattering peaks solely at 1.37 Å−1 originating from PVA (Supplementary Fig. 46)45. No additional XRD and WAXS peaks are found, suggesting the isolated chromophore nature in PVA doped films. The energy dispersive X-ray spectroscopy and elemental mapping images of 0.5 wt.% 2PACz@PVA film confirms the homogeneous dispersion of 2PACz within the PVA matrix, as evidenced by the uniform distribution of its characteristic N and P signals (Supplementary Fig. 47). Furthermore, owing to the homogeneous dispersion of chromophore in PVA films, SSPL spectra and afterglow quantum yields of multiple independently prepared 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films demonstrate high reproducibility (Supplementary Fig. 48 and Table 2). Compared to the O-H vibrational peaks at 3310 cm−1 of Raman spectra and at 3430 cm−1 of Fourier transform infrared (FTIR) in PVA film, slight blue shifted peak are observed in the FTIR (Supplementary Fig. 49 and Supplementary Fig. 50a) and Raman spectra (Fig. 3d and Supplementary Fig. 50b) of 2PACz@PVA, 4PACz@PVA, and 2CACz@PVA films46–49. Notably, 2PACz@PVA film demonstrates the most significant blue shift, indicating stronger hydrogen bond interaction between 2PACz and the PVA matrix. Meanwhile, the enhancement of hydrogen bond interaction also leads to the broadening of C-H stretching vibration47 at 2910 cm−1. This enhanced intermolecular interaction may play a vital role in endowing the improved afterglow properties of the isolated 2PACz molecules within the composite films. This important role of intermolecular interaction is further verified by varied polymeric matrices. Only SSPL could be captured when 2PACz, 4PACz, and 2CACz are doped into a non-polar polystyrene matrix, respectively (Supplementary Fig. 51). In contrast, the stronger and more abundant hydrogen bonds in polar polymeric matrices directly enhance both the SSPL and delayed PL intensities compared to their non-polar and weakly polar polymeric counterparts (Supplementary Fig. 52).

To gain deeper insight into the variations in intermolecular interactions, theoretical calculations were performed. The hydrogen bond strength in the molecular structure, which significantly impacts its photophysical properties, is influenced by the electronic effects such as electronegativity and molecular geometry50,51. The lower electronegativity of the phosphorus atom in the phosphate acid group results in a higher negative charge density on the oxygen atom in P=O and O-H of 2PACz compared to the oxygen atom in C=O and O-H of 2CACz (Supplementary Fig. 53 and Table 3), while the hydrogen atom on the hydroxyl group in 2PACz exhibits a higher positive charge density than that in 2CACz. The higher electrostatic potential (ESP) of the carbazole unit in 2PACz, compared to those in 4PACz and 2CACz, corresponds to its stronger computed binding energy with PVA (−282.65 kcal mol−1) (Supplementary Figs. 53 and 54, and Table 3). Furthermore, the phosphonic acid reveals more positive ESP values in 2PACz compared to the carboxyl group in 2CACz, which confers a higher binding energy between phosphonic acid and PVA (Supplementary Figs. 53 and 55, and Table 3). The directional interactions between 2PACz and PVA promote the formation of more linear hydrogen bonds, showing intersection angles between O-H---O of 156.8°, 157.6°, 170.5°, and 171.1°. These results lead to shorter and stronger hydrogen bond (Fig. 3e, f) as well as higher binding energy (Fig. 3e and Supplementary Fig. 56a–c) in 2PACz compared to those in 2CACz (Fig. 3g). In contrast, the long alkyl chain in 4PACz diminishes the electron-donating ability of the carbazole group. Consequently, the negative charge density of the oxygen atoms in the P=O and O-H groups of 4PACz is reduced (Supplementary Table 3), along with the reduced positive charge density on the hydrogen atom of the hydroxyl group. These results weaken the hydrogen bond interactions between 4PACz and PVA, as further evidenced by longer distances and smaller O-H---O intersection angles of 149.4°, 157.1°, and 167.5° (Fig. 3h) compared to those in the 2PACz@PVA film. Moreover, the extended alkyl chain in 4PACz hinders the formation of O-H---π type hydrogen bond between the PVA hydroxyl groups and the luminescent groups, which is a feature molecular interaction observed in 2PACz and 2CACz, resulting in weaker thermal stability for 4PACz52,53. Moreover, upon increasing the number of PVA chains from single to two and three, the binding energies between 2PACz and PVA are consistently higher than those of 4PACz and PVA (Supplementary Fig. 56d–i). Combining experimental and theoretical calculation results, the phosphine-mediated hydrogen bond interaction in 2PACz@PVA film plays a pivotal role in the construction of afterglow materials with improved luminescent features within the composite films.

Multicolor afterglow emission construction
Considering the ultralong lifetime of 3.05 s, blue afterglow emission with a wider range of 350–600 nm, as well as the good solubility and flexibility of 0.5 wt.% 2PACz@PVA film, this doped film could be a promising afterglow energy donor to construct versatile and colorful afterglow systems (Fig. 4a). Experimentally, water-soluble fluorescent dyes including fluorescein sodium (Fluc), rhodamine 123 (Rh123) and rhodamine 6G (Rh6G) were chosen as energy acceptors owing to the significant overlap between their absorption spectra and the delayed PL spectrum of 0.5 wt.% 2PACz@PVA film (Fig. 4b)26,54,55. The SSPL and delayed PL exhibit peaks at 538, 565, and 600 nm in Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA, respectively (Fig. 4c, d). As the concentration of fluorescent dyes increases, the emission peak of 2PACz@PVA in both SSPL and delayed PL spectra significantly diminishes (Supplementary Figs. 57–59), indicating the possibility of energy transfer from the singlet and triplet of 0.5 wt.% 2PACz@PVA to the doped fluorescence dyes. The optimized doping concentrations for Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA are 0.15, 0.25 and 0.15 wt.%, respectively, owing to their maximum delayed PL intensities. The SSPL and delayed PL spectra of Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA are almost identical to those of the corresponding Fluc, Rh123, and Rh6G doped PVA films, suggesting that the emerged peaks are attributed to the inherent emission of doped fluorescent dyes (Supplementary Fig. 60). The excitation-delayed PL mappings of 0.15 wt.% Fluc@2PACz@PVA, 0.25 wt.% Rh123@2PACz@PVA and 0.15 wt.% Rh6G@2PACz@PVA demonstrate nearly the same excitation range as the 2PACz@PVA (Supplementary Fig. 61), showing excitation wavelengths ranging from 220 to 350 nm. This means that these four doped films may have the same emission origin. Moreover, when directly exciting the fluorescent doped PVA films by 299 nm UV light, no observed afterglow emission can be captured, confirming the critical role of the energy donor of 2PACz@PVA film in triggering the multicolor afterglow emissions (Supplementary Fig. 62). Excitingly, this energy transfer process enables the afterglow emission to change from blue for 0.5 wt.% 2PACz@PVA to green (0.15 wt.% Fluc@2PACz@PVA), yellow (0.25 wt.% Rh123@2PACz@PVA), and red (0.15 wt.% Rh6G@2PACz@PVA) emissions as verified by the afterglow photographs (Supplementary Fig. 63), Commission International de l’Eclairage coordinates (Fig. 4e and Supplementary Fig. 64), and TRES spectra (Supplementary Fig. 65).

To further investigate the underlying mechanism of energy transfer, the lifetime analyses of 0.15 wt.% Fluc@2PACz@PVA, 0.25 wt.% Rh123@2PACz@PVA and 0.15 wt.% Rh6G@2PACz@PVA films were performed. The lifetimes at 370 nm have a significant decrease when the fluorescent guest is doped into 2PACz@PVA film at varied doping concentrations from 0.05 to 0.35 wt.% (Supplementary Fig. 66). Furthermore, the lifetimes of afterglow emission bands at 444 nm are decreased from 3.05 to 1.42 s for Fluc@2PACz@PVA films, from 3.05 to 0.80 s for Rh123@2PACz@PVA films, and from 3.05 to 1.15 s for Rh6G@2PACz@PVA films, respectively (Fig. 4f–h, Supplementary Figs. 67–69). Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA doped films exhibit no detectable long-lived afterglow when the fluorescent dyes are directly excited (Supplementary Fig. 70). These results indicate that non-radiative FRET process should be responsible for the multicolor afterglow emissions, enabling both FRET-dominated processes from the singlet and triplet excited states of the energy donor to the singlet excited state of the energy acceptor. Based on the amplitude lifetimes of fluorescence at 370 nm and the afterglow emission bands at 444 nm, the maximum FRET efficiencies of fluorescence can reach 29.8, 55.0, and 40.2%, and of afterglow can reach 59.2, 83.9, and 69.1% for Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA films, respectively (Supplementary Table 4).

Chiral multicolor afterglow emission exploration
To achieve COA emission, double-layer stacked polymeric films containing a top chiral polarizer of PLA layer and a bottom multicolor afterglow layer were constructed. These stacked films can be easily fabricated by spinning chiral PLA film onto multicolor afterglow films (Supplementary Fig. 71). Circularly polarized luminescence (CPL) spectra measurements are outlined in Supplementary Fig. 72a. As shown in Supplementary Figs. 73 and 74, using 0.5 wt.% 2PACz@PVA film as a model emitter, the concentrations of PLA solution were firstly optimized. Due to the largest dissymmetry factor (glum) of −3.0 × 10−2 (Fig. 5a–c), the optimized concentration of PLA is chosen as 100 mg mL−1, showing a corresponding thickness of 6.5 μm (Supplementary Fig. 75). The stacked films show much improved CPL performance than that of films prepared via direct doping of 2PACz@PVA into the PLA matrix (Supplementary Fig. 76). Furthermore, compared with recently reported CPOAmaterials (Supplementary Table 5), the glum achieved in 2PACz@PVA@D/L-PLA ranks among the highest values reported to date. Interestingly, due to the polarized feature of PLA film, reversed CPL signals could be achieved when the excitation UV light is placed in front of and behind the 2PACz@PVA@PLA film (Supplementary Figs. 72, 77 and 78)56–58. Therefore, distinct green, yellow, and red COA with emission peak at 538, 565, and 600 nm and glum of 5.2 × 10−3, 5.1 × 10−3, and 2.2 × 10−3 are achieved by spinning D/L-PLA films onto the top of 0.15 wt.% Fluc, 0.25 wt.% Rh123, and 0.15 wt.% Rh6G doped 2PACz@PVA films, respectively (Fig. 5d–f). Compared to the pure luminescent films, the stacked films coated with PLA polarizer show slightly decreased PLQYs (Supplementary Table 6). Exposure to high humidity substantially (Supplementary Fig. 79) reduces afterglow emissions. After 4 h of 365 nm irradiation, the afterglow retains ~77% intensity (Supplementary Fig. 80). Due to suppressed exciton thermal quenching (Supplementary Fig. 81), decreased temperature significantly enhances the CPL intensity. With the temperature increased, the CPL intensity of 2PACz@PVA@D/L-PLA is slightly decreased, which is much higher than that of 4PACz@PVA@D/L-PLA and 2CACz@PVA@D/L-PLA (Supplementary Fig. 82).

Potential applications of chiral multicolor afterglow polymers
Due to the efficient afterglow and chirality of the stacked polymers, luminescent coating film, anti-counterfeiting encryption, and writable afterglow ink were achieved. As shown in Fig. 6a, an aqueous solution of 2PACz@PVA is directly dropped onto the surface of coin (Supplementary Fig. 83), and after drying, afterglow films with visible surface details of the coin as well as flexibility and transparency are obtained (Supplementary Fig. 84).

Furthermore, a quick response (QR) code prepared through screen printing (Supplementary Fig. 85) is invisible due to background fluorescence interference. However, after removing the UV light, the QR code is clearly observed, and “COO” information can be readable by a mobile phone (Fig. 6b). Due to the appropriate water-solubility and long lifetime of 2PACz@PVA, 0.15 wt.% Fluc@2PACz@PVA, 0.25 wt.% Rh123@2PACz@PVA and 0.15 wt.% Rh6G@2PACz@PVA, the aqueous solutions were used as afterglow inks (Fig. 6c). Multicolor afterglow characters can be easily written and captured (Fig. 6d). By using 2PACz@PVA, Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA as emitters, a 3 × 4 encoding luminescent matrix was prepared. In principle, the color of blue, green, yellow, and red were defined as Morse code symbols of “●,” “●●,” “▬,” and “●▬,” respectively (Fig. 6e and Supplementary Text 1). Upon UV light irradiation, a luminescent matrix exhibits the information of “4VLP”. When the UV lamp is turned off, an afterglow encoded matrix with information of “4ALP” is captured. Moreover, due to the chiral polarizer of PLA, the chiral afterglow encoded information of “HELP” is observable, thereby achieving multiple encryptions.

Methods
Materials
Chemical reagents, unless otherwise specified, were purchased from Energy Chemical, Acros, or Alfa Aesar, and used without further purification. The polyvinyl alcohol (PVA) was purchased from Sigma-Aldrich (Mw = 85000-124000).

Preparation procedure of films
General fabrication procedure for fabricating 0.5 wt.% 2PACz@PVA (polyvinyl alcohol) film: Firstly, 2.5 mg of 2PACz was dissolved into 1 mL of ethanol. 0.5 g of PVA polymers was dissolved into 5 mL of distilled water and stirred at 90 °C for 0.5 h to obtain 100 mg mL−1 of PVA solution. 1 mL 2PACz ethanol solution was added into 5 mL of PVA aqueous solution and mixed at 90 °C for 0.5 h. Then, the mixture was dropped on a 2 × 2 cm2 quartz sheet and dried in an oven at 70 °C for 12 h to fabricate transparent polymer films for subsequent photophysical and morphological characterizations. The same procedure is used to obtain the 4PACz@PVA and 2CACz@PVA films with different doping concentrations.

Instrumentation
1H and 13C-nuclear magnetic resonance (NMR) spectra were recorded on a Bruker Ultra Shield Plus 400 MHz instrument with dimethyl sulfoxide (DMSO)-d6 as the solvent and tetramethyl silane as the internal standard. 31P-NMR was recorded on a Bruker Ultra Shield Plus 400 MHz instrument with DMSO-d6 as the solvent and phosphoric acid as the internal standard. Ultraviolet-visible absorption spectra were recorded on a Jasco V-750 spectrophotometer. Steady-state photoluminescence spectra were recorded on an Edinburgh FLS 1000 fluorescence spectrophotometer. The delayed PL spectra in dilute tetrahydrofuran were obtained using an Edinburgh FLS 1000 fluorescence spectrophotometer at 77 K in a dewar vessel with a 10 ms delay time using a microsecond (μs) flash lamp. The microsecond flash lamp produces short, typically a few μs, and high irradiance optical pulses for decay measurements in the range from microseconds to seconds. The delayed PL spectra and ultralong lifetimes were also measured using an Edinburgh FLS 1000 fluorescence spectrophotometer. For fluorescence lifetime measurements, a picosecond pulsed light-emitting diode (EPLED-290, wavelength: 300 nm; pulse width: 833.7 ps) was used. Excitation-PL mapping was measured using Hitachi F-4700 under ambient conditions. Powder X-ray diffractometry (XRD) patterns were measured using a Bruker D8 Advance diffractometer (Cu Kα: λ=1.5418 Å) under ambient conditions. The Fourier transform infrared (FTIR) spectra were obtained using Nicolet IN10 microspectroscopy (Thermo Fisher Scientific). The thickness of the chiral films was measured using a Dektak XT step meter, with a stylus scan range of 65 μm, a scanning length of 400 μm, a scan duration of 10 s, and a scan resolution of 0.13 μm. The intrinsic circularly polarized luminescence (CPL) spectra were investigated using a JASCO CPL-300 spectrometer. The scan speed was set as 500 nm min−1 with 0.1 nm resolution and a response time of 1.0 s.

Theoretical calculation
The geometric structure of the ground state was optimized using density functional theory. The frequency was then calculated and analyzed at the same level to confirm that the optimized geometric structure is a stable configuration. The excited state was calculated using time-dependent density functional theory using a universal B3LYP hybrid functional and 6-31G(d) basis set, and combining with DFT-D3 (BJ) dispersion correction due to the involvement of weak interactions. All theoretical calculations were performed under the Gaussian 09 D.01 package, and the frontier molecular orbitals were plotted using GaussView 6.0 software. The static potential and weak interaction energy were analyzed using the Multiwfn 3.8 package, and images of static potential and independent gradient model based on Hirshfeld partition were obtained through Visual Molecular Dynamics software. The spin-orbit coupling matrix elements between singlet and triplet states were calculated using ORCA software.

Data availability
The main data generated in this study are provided in the Source data file. The data that support the plots of this study are available from the corresponding author on request. Source data are provided with this paper.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "The manuscript presents the studies on the polyvinyl alcohol-based photoactive materials doped with phosphine acid\ncarbazole derivative (2PACz), stabilized within the PVA matrix through strong hydrogen bonding interactions formed\nbetween hydroxyl groups of PVA and phosphate groups. This stabilization leads to enhanced thermal stability and improved\nafterglow emission efficiency. The blue emission can be further red-shifted by introducing a second dopant, selected from\ncommon organic dyes including fluorescein sodium, rhodamine 123, and rhodamine 6G, resulting in green, yellow, and red\nafterglow emissions, respectively. Subsequently, the authors achieved chiral emission through the layering the light\npolarizer (chiral polylactide, PLA), on the top of the emissive layer. The exemplary applications of the obtained COA\nmaterials have been effectively demonstrated. The photophysical properties of the synthesized materials are thoroughly\ncharacterized, including analyses of total and afterglow luminescence at varying concentrations of PACz and dye dopants,\nmulti-temperature experiments, quantum chemical calculations, and circularly polarized luminescence studies. The results\nfor 2PACz-based materials are comprehensively compared with those for the 4PACz derivative (bearing a longer aliphatic\nlinker) and the carboxylic acid analogue 2CACz.\nOverall, this is an interesting and relevant contribution suited for publication in a materials-oriented chemistry journal. The\ncircularly polarized organic afterglow materials currently received a lot of interest due to their applications in optoelectronics,\ndata storage and encryption devices. Through the supramolecular engineering approach, the authors achieved enhanced\nafterglow emission at elevated temperature for 2PACz@PVA compared to 4PACz@PVA and 2CACz@PVA counterparts,\nwhich is in my opinion the most important aspect of this study. The second achievement is the application of the CPOA\nmaterials in selected encryption devices. Nevertheless, the level of presented novelty is not sufficient for a high-impact\njournal such as Nature Communications. While the authors report some improvements over previously investigated systems\n(e.g., boronic and carboxylic acid-functionalized carbazole-doped polymers), the enhancements observed for\n2PACz@PVA are only modest. The photoluminescence and phosphorescence quantum yields for best performing material 2PACz(0.5\nwt.%)@PVA (PLQY = 33.3% and phQY = 7.1%), are in fact comparable to the values obtained for the analogues materials\n4PACz(0.5 wt.%)@PVA (PLQY = 30.3% and phQY = 7.1%) and 2CACz(0.5 wt.%)@PVA (PLQY = 30.1% and phQY = 6.5%).\nPLQY and afterglow QY are in general moderate and rather typical for carbazole-doped polymers. Similarly, the use of a\npolarizer to achieve polarized light emission is a standard approach and does not represent a significant methodological\nadvance. The dissymmetry factor of 0.03 is moderately high but it does not exceeds the values reported for other CPOA\nmaterials. I also have some reservations regarding the conclusions drawn about binding energies from the quantum\nchemical calculations as, from the presented data, it does not properly address the differences between performance of two\nphosphate-based carbazole derivatives, 2PACz and 4PACz. Furthermore, the scientific quality of the manuscript and SI\ncould be improved for greater clarity and completeness:\n1. The described preparation methodology indicates that the materials may contain significant amounts of water and ethanol.\nSuch additives may disrupt the hydrogen bonds between PVA and dopants, and also affect the photoactive properties\n(SSPL QY and afterglow QY) of the material. It should be stressed that PVA exhibit partial crystallinity, which usually affect\nthe quality of the obtained films. This raises concerns on the repeatability of the preparation procedure leading the material\nof the uniform composition and properties. It should be stress that the photoluminescence and afterglow quantum yields are\ncomparable between 2PACz@PVA, 4PCAz@PVA and CACz@PVA thus even minor variations in material composition or\nadditives could affect the observed trends. I recommend to perform TGA thermal analysis and elemental analysis to better\nquantify the possible presence of solvent additives. The 1H NMR in D2O can be also performed to check the presence of\nresidual ethanol and confirm the composition of the material. The authors may also consider to employ EDX method to\nfurther confirm the homogeneous distribution of the dopant within the PVA matrix. At a doping level of 0.5wt.%, PXRD may\nnot be sensitive enough to detect Bragg diffraction from aggregation states or plausible crystalline phase extrusion.\n2. Based on postulated improved afterglow emission and increased temperature stability resulted from the stronger\nhydrogen-bond interactions between 2PCAz and PVA, it could be expected that all three compounds behave similarly in\nnon-polar environment. Thus I recommend to use non-polar matrices such as polystyrene or zeonex (0.5 wt.% dopant\nconcentrations) and compare these with PVA-based materials. Additionally, experiments using other polar matrices\npossessing hydrogen-bond donor or acceptor sites such as PMMA or PCL, would further strengthen the conclusions on the\neffect of hydrogen bond interactions on the luminescent properties of compounds.\n3. The reported changes in the O-H and C-H stretching bands in Raman and FTIR spectra, attributed to dopant-PVA\ninteractions, appear minor (if any) and, at studied concentrations, are likely not significant.\n4. The computational part should be revised. The interaction energy between two molecules strongly depends on the spatial\norientation of the molecules. The latter can be affected by the optimisation procedure, the starting geometries of the\nmolecules, and the length of the PVA chain. The geometry of hydrogen bonding also depends on spatial orientation of the\nmolecules. It seems the orientation of 4PACz may not be optimal (local minimum) relative to the PVA chain (Figure 3g),\nparticularly when compared to 2PACz (Figure 3e), which is bent and interact via additional C-H···C(p) and O-H···C(p)\ninteractions with the carbazole p-system. One might expect that 4PACz would be involved in similar interactions as 2PACz,\nresulting in comparable binding energies. Furthermore, the molecule may be engaged in multiple interactions with\nneighbouring PVA chains. Thus I would expect that 4PACz would exhibit similar total interaction energy as 2PACz.\nI additionally suggest improving this section by comparing partial atomic charges or total group charges (e.g., for the\ncarbazole unit) for single molecules of 2PACz, 4PACz, and 2CACz.\n5. The polarizer typically reduces transmitted light. Quantum yield values should be provided for the final materials coated\nwith PLA polarizer. In addition, it is not clear why some PLQY values for dye-doped 2PACz@PVA are similar (or even\nhigher) that the value for the non-dye doped 2PACz@PVA (Table S3, last column), which is slightly unexpected considering\nthe efficiency of FRET.\n6. The synthesis and characterization of the studied compounds should be supplemented with additional information:\na) Please provide the information on reaction yields.\nb) 1H, 13C NMR and HR-MS spectra should be provided for all new compound including intermediate compounds. In case\nthe compound is already known in the literature, its structure should be confirmed by 1H NMR analysis. The literature\ncitation to the existed procedure should be provided. If the currently used procedures are not identical with the literature\nones, full description should be provided along with the 1H and 13C NMR data. Copies of all NMR and HRMS spectra\nshould be supplemented in SI.\nMinor issues:\n1. Main article:\na) Page 2: Synthesis and characterization: 2PACz and 4PACz were obtained in three steps.\nb) Figure 1c. The drawing is not clear and lack of consistency with the procedure presented in SI and Scheme S3.\nc) Figure 2d: The quality factor is not defined.\nd) Page 3: afterglow mechanism analysis: The quantum yields and afterglow lifetimes for 4PACz and 2CACz at the optimal\nconcentrations in PVA should be provided in the main text aside the values discussed for 2PACz.\ne) Page 3: afterglow mechanism analysis: “2PACz@PVA film exhibits much enhanced afterglow intensities and lifetimes\nthan those of 4PACz and 2CACz doped PVA films, which may be due to the additional n-π* transition contribution of oxygen\natom in P=O in the frontier molecular orbital distributions of 2PACz, thus enabling much larger spin orbit coupling constants\nof 2PACz than that of 4PACz and 2CACz”. However, from Figure S13 it seems that the contribution of the P=O oxygen atom\nto the HOMO is insignificant. In addition, the S1-Tn SOC values (Figure S14) are generally higher for 2CACz than for\n2PACz. It should be noted that in 2PACz and 4PACz, two carbon atoms from the alkyl chain contribute to the HOMO, while\nin 2CACz, the distribution also extends over the carboxylic group.\nf) Page 4: “The stronger electron-donating ability of the phosphorus atom in the phosphate group results in a higher negative\ncharge density on the oxygen atom in P=O and O-H of 2PACz compared to the oxygen atom in C=O and O-H of 2CACz”. It\nis more convenient to discuss differences between -P(O)(OH)2 and COOH groups in terms of the lower electronegativity of\nphosphorus and the more polar nature of P=O / P-OH bond compared to C=O / C-OH.\n2. Supporting Information:\na) Figures S1 and S3: It seems that the phase correction should be performed.\nb) Figure S7. Please indicate the excitation wavelength and concentration of the compound.\nc) Figure S19. The figure caption should describe all shapes presented, including those presumably visualizing non-\ncovalent interaction index (NCI).\nd) Please indicate the eluent in chromatography purification procedures. Please indicate the solvent used in the\nrecrystallization of 2PACz and Cz-2-Br.\ne) It would be beneficial if authors provide the 31P NMR spectra for 2PACz and 4PACz.\nf) The chemical shifts for 13C NMR should be given to the first decimal place.\ng) Table S3: PLQY values should be given to the first decimal place.\nh) Metling temperature should be specified for all solid compounds.\ni) The energy values for HOMO and LUMO levels should be provided.", "reviewer_2": "The manuscript presents a novel approach for enhancing chiral organic afterglow (COA) materials by leveraging phosphine-\nmediated hydrogen bonds, which significantly improve afterglow emission and thermal stability. The use of energy transfer\nmechanisms facilitates the development of multicolor afterglow emissions, making the material highly suitable for\napplications in anti-counterfeiting and encryption. Given the novelty and broad interest of this work, I recommend its\nacceptance in Nature Communications as it provides valuable insights into the field of COA materials. Although the study is\nwell-investigated and organized, based on systematic theoretical and experimental results, a few minor revisions are\nrecommended:\n1. The abbreviation \"m-\" in Supplementary Figure S11 typically represents the meta position in organic chemistry. The\ncorresponding methyl abbreviation should be modified to \"Me-\".\n2. Can long-lived afterglow emission be achieved by directly exciting the doped fluorescence dyes?\n3. The long-term stability of the hydrogen bonds and their performance under different environmental conditions (e.g.,\ntemperature variation, humidity) need further exploration.\n4. The role of the interfacial chiral polylactic acid (PLA) layer in maintaining chiral amplification and enhancing the material's\nafterglow efficiency is intriguing, but additional details on its impact under various conditions would be beneficial.\n5. While the manuscript is well-organized and the experimental data are robust, some minor grammatical revisions are\nneeded to enhance clarity and readability.\n6. Can chiral afterglow emission be achieved by directly doping 2PACz@PVA into the PLA matrix?\nThese revisions will further strengthen the manuscript, and I believe it has great potential for publication."}, "author_response": "Comment 1.1: The manuscript presents the studies on the polyvinyl alcohol-based\nphotoactive materials doped with phosphine acid carbazole derivative (2PACz),\nstabilized within the PVA matrix through strong hydrogen bonding interactions\nformed between hydroxyl groups of PVA and phosphate groups. This stabilization\nleads to enhanced thermal stability and improved afterglow emission efficiency. The\nblue emission can be further red-shifted by introducing a second dopant, selected\nfrom common organic dyes including fluorescein sodium, rhodamine 123, and\nrhodamine 6G, resulting in green, yellow, and red afterglow emissions, respectively.\nSubsequently, the authors achieved chiral emission through the layering the light\npolarizer (chiral polylactide, PLA), on the top of the emissive layer. The exemplary\napplications of the obtained COA materials have been effectively demonstrated. The\nphotophysical properties of the synthesized materials are thoroughly characterized,\nincluding analyses of total and afterglow luminescence at varying concentrations of\nPACz and dye dopants, multi-temperature experiments, quantum chemical\ncalculations, and circularly polarized luminescence studies. The results for 2PACz-\nbased materials are comprehensively compared with those for the 4PACz derivative\n(bearing a longer aliphatic linker) and the carboxylic acid analogue 2CACz.\nOverall, this is an interesting and relevant contribution suited for publication in\na materials-oriented chemistry journal. The circularly polarized organic afterglow\nmaterials currently received a lot of interest due to their applications in\noptoelectronics, data storage and encryption devices. Through the supramolecular\nengineering approach, the authors achieved enhanced afterglow emission at elevated\ntemperature for 2PACz@PVA compared to 4PACz@PVA and 2CACz@PVA\ncounterparts, which is in my opinion the most important aspect of this study. The\nsecond achievement is the application of the CPOA materials in selected encryption\ndevices.\nAuthor reply: We extend our sincere thanks for the reviewer's thoughtful summary\nand positive evaluation. We are grateful that the reviewer regards our work as an\ninteresting and relevant contribution study to circularly polarized organic\nafterglow (CPOA) materials. We appreciate the recognition of our work, specifically\nregarding the robustness of the characterization and the effectiveness of the\nsupramolecular engineering approach in realizing high-temperature CPOA for\nadvanced encryption devices.\nComment 1.2: Nevertheless, the level of presented novelty is not sufficient for a high-\nimpact journal such as Nature Communications. While the authors report some\nimprovements over previously investigated systems (e.g., boronic and carboxylic acid-\nfunctionalized carbazole-doped polymers), the enhancements observed for\n2PACz@PVA are only modest. The photoluminescence and phosphorescence\nquantum yields for best performing material 2PACz(0.5 wt.%)@PVA (PLQY = 33.3% and\nphQY = 7.1%), are in fact comparable to the values obtained for the analogues\nmaterials 4PACz(0.5 wt.%)@PVA (PLQY = 30.3% and phQY = 7.1%) and 2CACz(0.5\nwt.%)@PVA (PLQY = 30.1% and phQY = 6.5%). PLQY and afterglow QY are in general\nmoderate and rather typical for carbazole-doped polymers.\nAuthor reply: We thank the reviewer for their thoughtful comments, which can\nhelp us to improve the quality and raise the impact of our work. We have carefully\nconsidered the point regarding the degree of novelty and the comparative\nquantum yields among the different doped systems. While it is true that the\nabsolute photoluminescence quantum yield (PLQY) and afterglow quantum yield\n(QY) values of 2PACz@PVA are comparable to those of the 4PACz@PVA, and\n2CACz@PVA analogues at room temperature, the key advancement of our work\nlies in the superior properties of 2PACz@PVA under thermally stressed conditions.\nThe denser and more robust hydrogen bond network between 2PACz and PVA\nmatrix more effectively suppresses non-radiative decay of triplet excitons, yielding\na significantly enhanced afterglow lifetime and duration than 4PACz@PVA and\n2CACz@PVA, particularly at elevated temperatures.\nTo capture practical performance beyond PLQY, we introduce a figure of merit\ndefined as 𝑄 FM =PLQY×𝜏 A, where 𝜏 A is the afterglow lifetime. Notably, as shown in\nSupplementary Figure 38, the 2PACz@PVA film demonstrates a markedly higher\n𝑄 , underscoring its more balanced and efficient luminescent properties. We\nFM\nbelieve that this combination of extended lifetime, enhanced thermal stability, and\na higher overall 𝑄 represents a meaningful step forward in the design of stable\nFM\nand efficient CPOA materials. We hope this clarification alleviates the reviewer's\nconcern.\nAdded text: Therefore, the 2PACz@PVA film demonstrates a higher 𝑄 ,\nFM\nunderscoring its more exceptional and efficient luminescent properties\n(Supplementary Fig. 38).\nAdded figure:\nSupplementary Figure 38. The figure of merit of 0.5 wt.% 2PACz@PVA,\n4PACz@PVA and 2CACz@PVA films.\nComment 1.3: Similarly, the use of a polarizer to achieve polarized light emission is a\nstandard approach and does not represent a significant methodological advance. The\ndissymmetry factor of 0.03 is moderately high but it does not exceeds the values\nreported for other CPOA materials.\nAuthor reply: We appreciate the reviewer's comment regarding the CPL\nimplementation. While the use of an external polarizer is a standard technique, the\nobjective here is to demonstrate that our highly stable, temperature-resistant\nafterglow system could be conveniently and effectively integrated with such a\npolarizer film to produce CPOA. As shown in Supplementary Figure 77, with the\ntemperature increased, both the CPL intensity and g value of 2PACz@PVA@D/L-\nlum\nPLA are slightly decreased, which are much higher than those of 4PACz@PVA@D/L-\nPLA and 2CACz@PVA@D/L-PLA. Moreover, a comparison with recently reported\nCPOA materials (Supplementary Table 5) reveals that our achieved g of 0.03\nlum\nranks among the highest values reported. It is superior to most existing\ncounterparts and is only lower than the values achieved by a few specialized liquid\ncrystal-based CPOA systems. In contrast, the lifetime of CPOA materials in our work\nis much larger than that of the liquid crystal-based CPOA systems. Interestingly,\nwhen we chose liquid crystal as an external polarizer, the g can reach 0.85\nlum\n(Figure R1). These results demonstrate that our CPOA material represents a\ncompetitive performance within the emerging field of CPOA materials. Our focus is\non achieving a balanced combination of afterglow duration, thermal robustness,\nand appreciable chirality, which we have successfully demonstrated in a single\nmaterial system, constituting a meaningful step forward. We hope these added\nexperiments and discussions can clarify the reviewer’s concerns.\nFigure R1. The CPL spectra of 2PACz@PVA/R(S)-liquid crystal (LC).\nAdded text: With the temperature increased, the CPL intensity of\n2PACz@PVA@D/L-PLA is slightly decreased, which is much higher than that of\n4PACz@PVA@D/L-PLA and 2CACz@PVA@D/L-PLA (Supplementary Fig. 77).\nAdded text: Furthermore, compared with recently reported CPOA materials\n(Supplementary Table 5), the g achieved in 2PACz@PVA@D/L-PLA ranks among\nlum\nthe highest values reported to date.\nAdded figure:\nSupplementary Figure 77. The CPL spectra of 2PACz@PVA@D/L-PLA (a),\n4PACz@PVA@D/L-PLA (b) and 2CACz@PVA@D/L-PLA (c) at varied temperatures.\nAdded table:\nSupplementary Table 5. Summary of the afterglow lifetimes and dissymmetry\nfactors (g ) of CPOA materials in recently reported works.\nlum\nMaterial type Reference Lifetime g\nlum\nAngew. Chem. Int. Ed. 2025, 65, e202510153. 944 ms 0.0035\nAdv. Optical. Mater. 2025, 13, 2402522. 28.48 ms 0.065\nJ. Mater. Chem. C 2023, 11, 4846. 160 ms 0.005\nChem. Eng. J. 2021, 421, 129732. 109 ms 0.0008\nAngew. Chem. Int. Ed. 2022, 61, e202213130. 2200 ms 0.0052\nACS Appl. Polym. Mater. 2024, 6, 9582. 252 ms -0.0071\nAdv. Mater. 2025, 37, 2500953. 770 ms 0.003\nAdv. Optical Mater. 2024, 12, 2302482. 1017 ms 0.0021\nNat. Commun. 2024, 15, 3053. 3000 ms 0.0102\nAngew. Chem. Int. Ed. 2022, 61, e202202977. 560 ms 0.12\nConventional J. Phys. Chem. Lett. 2016, 7, 1539. 670 ms 0.0023\nCPOA Material Angew. Chem. Int. Ed. 2020, 132, 4786. 600 ms 0.0023\nJ. Phys. Chem. Lett. 2025, 16, 9568. 137 ms 0.073\nChem. Eng. J. 2021, 418, 129167. 592 ms 0.0026\nNat. Commun. 2022, 13, 429. 587 ms 0.0023\nSmall, 2023, 19, 2303579. 946 ms 0.0042\nACS Appl. Mater. Interfaces 2023, 15, 49623. 650 ms 0.0035\nACS Nano. 2023, 17, 6912. 1230 ms 0.012\nJ. Am. Chem. Soc. 2021, 143, 18527. 680 ms 0.0094\nJ. Mater. Chem. C 2024, 12, 9578. 1730 ms 0.011\nACS Appl. Polym. Mater. 2025, 7, 9422. 658 ms 0.008\nNat. Commun. 2024, 15, 7149. 862 ms 0.006\nAdv. Funct. Mater. 2025, 35, 2424404. 125 ms 1.6\nLiquid Crystal\nCPOA Material Adv. Funct. Mater. 2025, 35, 2506911. 371 ms 0.59\nCell Rep. Phys. Sci. 2023, 4, 101583. 548 ms 0.93\nAdv. Mater. 2024, 36, 2306834. 735 ms 1.49\nJ. Mater. Chem. C 2023, 11, 4104. 1080 ms 0.098\nAdv. Opt. Mater. 2025, 13, e01631. 1713 ms -0.2541\nACS Appl. Mater. Interfaces 2023, 15, 26037. 1250 ms 1.09\nAngew. Chem. Int. Ed. 2024, 63, e202319536. 805 ms 1.38\nACS Nano. 2025, 19, 11221. 2040 ms -0.749\nAdv. Opt. Mater. 2025, 13, 2403468. 823 ms -0.35\nAdv. Opt. Mater. 2023, 11, 2300745. 567 ms -0.19\nJ. Phys. Chem. Lett. 2025, 16, 10142. 730 ms 0.7\nComment 1.4: I also have some reservations regarding the conclusions drawn about\nbinding energies from the quantum chemical calculations as, from the presented data,\nit does not properly address the differences between performance of two phosphate-\nbased carbazole derivatives, 2PACz and 4PACz.\nAuthor reply: We appreciate the reviewer's point on the binding energy analysis.\nTo specifically address the relationship between binding energy and afterglow\nperformance, we have performed more comprehensive quantum chemical\ncalculations considering the interaction of 2PACz/4PACz with multiple PVA chains.\nBoth 2PACz and 4PACz reveal increased binding energies when the PVA chain\nincreases from single to two and three (Supplementary Figure 53). Notably, the\nbinding energies of 2PACz/PVA system are always higher than those of 4PACz/PVA\nsystem. Besides, the optimized geometric structures of 2PACz/4PACz in three PVA\nchains indicate that the alkyl chain in 2PACz is still oriented perpendicular to the\ncarbazole ring, whereas 4PACz adopts a more linear conformation. This structural\ndistinction facilitates the formation of a denser and more rigid hydrogen bond\nnetwork between 2PACz and PVA. In contrast, the longer alkyl chain in 4PACz\nallows for improved flexibility, resulting in a more dynamic and less robust binding\ninteraction between 4PACz and PVA. The additional theoretical calculations\nconfirm again that the higher binding energies play a critical role in boosting\nenhanced afterglow properties in 2PACz/PVA system than that of 4PACz/PVA\nsystem. We have added the additional theoretical calculations and explanation into\nthe revised manuscript. We hope these results can clarify the reviewer’s concerns.\nAdded text: Moreover, upon increasing the number of PVA chains from single to\ntwo and three, the binding energies of 2PACz@ PVA are consistently higher than\nthose of 4PACz@PVA and 2CACz@PVA (Supplementary Fig. 53d-i).\nUpdated figure：\nSupplementary Figure 53. Theoretical calculated binding energies of 2PACz (a, d,\ng), 2CACz (b, e, h) and 4PACz (c, f, i) with one (a-c), two (d-f) and three (g-i) PVA\nchains. Note: For the NCI, red represents repulsive interactions, green represents\nvan der Waals interactions, and blue represents attractive interactions.\nComment 1.5: Furthermore, the scientific quality of the manuscript and SI could be\nimproved for greater clarity and completeness:\nAuthor reply: Thanks for the professional suggestions, which can help us to\nimprove the quality and raise the impact of our work. We have carefully addressed\nthese points according to the suggestion.\n1.1 The described preparation methodology indicates that the materials may contain\nsignificant amounts of water and ethanol. Such additives may disrupt the hydrogen\nbonds between PVA and dopants, and also affect the photoactive properties (SSPL QY\nand afterglow QY) of the material. It should be stressed that PVA exhibit partial\ncrystallinity, which usually affect the quality of the obtained films. This raises concerns\non the repeatability of the preparation procedure leading the material of the uniform\ncomposition and properties. It should be stress that the photoluminescence and\nafterglow quantum yields are comparable between 2PACz@PVA, 4PCAz@PVA and\nCACz@PVA thus even minor variations in material composition or additives could\naffect the observed trends. I recommend to perform TGA thermal analysis and\nelemental analysis to better quantify the possible presence of solvent additives.\nAuthor reply: Thanks for the professional comments of the reviewer. As\nrecommended, we performed thermogravimetric analysis (TGA) to detect and\nquantify any residual solvent or water in the 2PACz@PVA, 4PCAz@PVA and\n2CACz@PVA films. The TGA curves of these doped films show no significant mass\nloss up to 200°C (Supplementary Figure 28), effectively ruling out the presence of\nvolatile components such as water or ethanol that could influence their\nphotophysical properties. Furthermore, the steady-state photoluminescence (SSPL)\nand QYs for multiple independently prepared batches of 2PACz@PVA,\n4PACz@PVA and 2CACz@PVA films are highly reproducible within experimental\nerror, indicating that small variations in film preparation do not alter the observed\ntrends (Supplementary Figure 45 and Supplementary Table 2). We have updated\nthe manuscript and the Supplementary Information with these added results. Many\nthanks.\nAdded text: Thermogravimetric analysis of the 2PACz@PVA, 4PACz@PVA and\n2CACz@PVA films shows no significant mass loss up to 200°C (Supplementary Fig.\n28), and no ethanol peaks are detected in the ¹H NMR spectrum of the 2PACz@PVA\nfilm (Supplementary Fig. 29). These results collectively exclude any influence of\nvolatile solvents on the observed luminescence properties.\nAdded text: Furthermore, owing to the homogeneous dispersion of chromophore\nin PVA films, SSPL spectra and afterglow quantum yields of multiple independently\nprepared 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films demonstrate high\nreproducibility (Supplementary Fig. 45 and Table 2).\nAdded figures:\nSupplementary Figure 28. The thermogravimetric analysis curves of 0.5 wt.%\n2PACz@PVA, 4PACz@PVA, and 2CACz@PVA films.\nSupplementary Figure 45. The SSPL spectra of multiple independently prepared\nbatches of 0.5 wt.% 2PACz@PVA (a), 0.5 wt.% 4PACz@PVA (b) and 0.5 wt.%\n2CACz@PVA (c) films.\nAdded table:\nSupplementary Table 2. The afterglow quantum yields (QYs) for multiple\nindependently prepared batches of 2PACz@PVA, 4PACz@PVA and 2CACz@PVA\nfilms.\nQYs (%)\nBatches\n2PACz@PVA 4PACz@PVA 2CACz@PVA\n1 6.9 6.2 5.7\n2 6.7 6.2 5.6\n3 6.8 6.4 5.4\n4 6.6 6.1 5.5\n1.2 The 1H NMR in D2O can be also performed to check the presence of residual ethanol\nand confirm the composition of the material.\nAuthor reply: We sincerely thank the reviewer for this valuable suggestion. To\nverify the absence of residual ethanol and confirm the material composition, we\nperformed 1H nuclear magnetic resonance (NMR) spectroscopy in D O. As shown\n2\nin Supplementary Figure 29, the signals in the range of 1.5-2.1 ppm and 3.5-4.0 ppm\nare assigned to the protons of the PVA methylene (CH ) and the methine (CH),\n2\nrespectively. Additionally, the aromatic signals observed in the range of 7.25-8.25\nppm are assigned to 2PACz. It is notable that the characteristic peaks of ethanol,\nspecifically the methyl triple peak expected around 1.1 ppm, are not detected.\nThese results confirm again that the luminescent performance of the 2PACz@PVA\nfilm is not affected by residual ethanol solvent. We hope our added results can\naddress your concerns. Many thanks.\nAdded text: Thermogravimetric analysis of the 2PACz@PVA, 4PACz@PVA and\n2CACz@PVA films shows no significant mass loss up to 200°C (Supplementary Fig.\n28), and no ethanol peaks are detected in the ¹H NMR spectrum of the 2PACz@PVA\nfilm (Supplementary Fig. 29). These results collectively exclude any influence of\nvolatile solvents on the observed luminescence properties.\nAdded figure:\nSupplementary Figure 29. 1H NMR spectrum of 0.5 wt.% 2PACz@PVA in D O.\n2\n1.3 The authors may also consider to employ EDX method to further confirm the\nhomogeneous distribution of the dopant within the PVA matrix. At a doping level of\n0.5wt.%, PXRD may not be sensitive enough to detect Bragg diffraction from\naggregation states or plausible crystalline phase extrusion.\nAuthor reply: We thank the reviewer for this insightful suggestion. Energy\ndispersive X-ray spectroscopy and elementary mapping images were conducted on\nthe 0.5 wt.% 2PACz@PVA film to probe the distribution of 2PACz. As shown in\nSupplementary Figure 44, the elemental mapping images for nitrogen (N) and\nphosphorus (P), which are the characteristic elements of 2PACz, are both\nhomogeneously distributed across the entire analyzed region. Moreover, the wide-\nangle X-ray scattering (WAXS) measurements of 2PACz@PVA film show almost\nidentical pattern to that of PVA film, showing a scattering peak at 1.37 A−1\noriginating from PVA film (Supplementary Figure 43). These results provide direct\nevidence of the uniform dispersion of the dopant in the PVA matrix at this\nconcentration. Given the low doping level (0.5 wt.%), aggregation of the\nchromophore is unlikely, which is consistent with previously reported results (J. Am.\nChem. Soc. 2021, 143, 13675; Nat. Commun. 2022, 13, 347; Angew. Chem. Int. Ed. 2025,\n64, e202510153). Therefore, no additional peaks are observed in PXRD and WAXS\nmeasurements. We have updated the discussion section in the revised manuscript\naccordingly. Many thanks.\nAdded text: This is further supported by wide-angle X-ray scattering (WAXS)\nmeasurements, which show scattering peaks solely at 1.37 Å-1 originating from PVA\n(Supplementary Fig. 43).\nAdded text: The energy dispersive X-ray spectroscopy and elemental mapping\nimages of 0.5 wt.% 2PACz@PVA film confirms the homogeneous dispersion of\n2PACz within the PVA matrix, as evidenced by the uniform distribution of its\ncharacteristic N and P signals (Supplementary Fig. 44).\nAdded figures:\nSupplementary Figure 43. 2D-wide-angle X-ray scattering (WAXS) pattern (a) and\nWAXS spectrum (b) of 2PACz@PVA film.\nSupplementary Figure 44. Energy dispersive X-ray spectroscopy and elemental\nmapping images of 0.5 wt.% 2PACz@PVA film.\n2. Based on postulated improved afterglow emission and increased temperature\nstability resulted from the stronger hydrogen-bond interactions between 2PCAz and\nPVA, it could be expected that all three compounds behave similarly in\nnon-polar environment. Thus I recommend to use non-polar matrices such as polystyrene or\nzeonex (0.5 wt.% dopant concentrations) and compare these with PVA-based\nmaterials. Additionally, experiments using other polar matrices possessing hydrogen-\nbond donor or acceptor sites such as PMMA or PCL, would further strengthen the\nconclusions on the effect of hydrogen bond interactions on the luminescent\nproperties of compounds.\nAuthor reply: We thank the reviewer for this excellent and insightful suggestion.\nTo systematically investigate the effect of polymer polarity and hydrogen bond\ndonor or acceptor sites on the luminescent properties of 2PACz, we prepared a\nseries of doped polymer films. The matrices span a range of polarities, from non-\npolar polystyrene (PS), to weak polar poly(methyl methacrylate) (PMMA) and\npolycaprolactone (PCL), and finally to strongly polar poly(vinyl alcohol) (PVA),\npoly(acrylic acid) (PAA), and polyacrylamide (PAM). As shown in Supplementary\nFigure 48, when doping 2PACz, 4PACz, and 2CACz into a PS matrix at a 1:200 mass\nratio, only SSPL could be captured, which suggests their similar behavior in a non-\npolar environment. Furthermore, when 2PACz is doped into polar matrices of PVA,\nPAM, and PAA films, respectively, both the fluorescence and afterglow intensities\nare significantly enhanced (Supplementary Figure 49). In contrast, only weak\nfluorescence and no detectable afterglow are found when 2PACz is doped into less\npolar or non-polar polymers of PMMA, and PCL due to their non-polar nature and\nlack of sufficient hydrogen bond sites. Due to the presence of strong hydrogen\nbond networks, the 2PACz@PAM film also exhibits good thermal stability (Figure\nR2). These results provide compelling evidence that the emergence of afterglow is\ndirectly governed by the strength and abundance of hydrogen bond interactions\nwithin the system. The added experiments and discussions have been added in the\nrevised manuscript and Supplementary Information. Many thanks.\nFigure R2: Temperature-dependent delayed PL intensity ratios (I\nT\n/I 30℃) of 0.5 wt.%\n2PACz@PVA and 0.5 wt.% 2PACz@PAM films.\nAdded text: This important role of intermolecular interaction is further verified by\nvaried polymeric matrices. Only SSPL could be captured when 2PACz, 4PACz, and\n2CACz are doped into a non-polar polystyrene matrix, respectively (Supplementary\nFig. 48). In contrast, the stronger and more abundant hydrogen bonds in polar\npolymeric matrices directly enhance both the SSPL and delayed PL intensities\ncompared to their non-polar and weakly polar polymeric counterparts\n(Supplementary Fig. 49).\nAdded figures:\nSupplementary Figure 48. SSPL spectra of 2PACz@PS (polystyrene), 4PACz@PS\nand 2CACz@PS at a 1:200 mass ratio.\nSupplementary Figure 49. SSPL (a) and delayed PL (b) spectra of 2PACz doped in\ndifferent polymeric matrices at a 1:200 mass ratio. Matrices: polyacrylamide (PAM),\npolyacrylic acid (PAA), polymethyl methacrylate (PMMA), and polycaprolactone\n(PCL).\n3. The reported changes in the O-H and C-H stretching bands in Raman and FTIR spectra,\nattributed to dopant-PVA interactions, appear minor (if any) and, at studied concentrations,\nare likely not significant.\nAuthor reply: We sincerely appreciate the reviewer's valuable comment. In the\nFourier transform infrared (FTIR) spectra, the broad O-H stretching band of PVA at\n~3430 cm-1 shows a clear and progressive blue-shift to 3458 cm-1 upon doping with\nchromophores. This shift reflects a modified hydroxyl environment, and it is largest\nfor 2PACz@PVA, consistent with the strongest P=O···H-O interaction\n(Supplementary Figure 47). Similarly, in the Raman spectra, the O-H stretching\nband near 3378 cm-1 shifts to 3415 cm-1 for 2PACz@PVA, a change more pronounced\nthan for 2CACz or 4PACz. Both FTIR and Raman spectra strongly suggest\nstrengthened hydrogen bonds and intermolecular interactions between 2PACz and\nPVA. We hope our answers can address the reviewer’s concerns. Many thanks.\nAdded figure:\nSupplementary Figure 47. Normalized FTIR (a) and Raman (b) spectra of PVA, 0.5\nwt.% 2PACz@PVA, 0.5 wt.% 4PACz@PVA and 0.5 wt.% 2CACz@PVA films.\n4.1 The computational part should be revised. The interaction energy between two\nmolecules strongly depends on the spatial orientation of the molecules. The latter can\nbe affected by the optimisation procedure, the starting geometries of the molecules,\nand the length of the PVA chain. The geometry of hydrogen bonding also depends on\nspatial orientation of the molecules. It seems the orientation of 4PACz may not be\noptimal (local minimum) relative to the PVA chain (Figure 3g), particularly when\ncompared to 2PACz (Figure 3e), which is bent and interact via additional C-H···C(p) and\nO-H···C(p) interactions with the carbazole p-system. One might expect that 4PACz\nwould be involved in similar interactions as 2PACz, resulting in comparable binding\nenergies. Furthermore, the molecule may be engaged in multiple interactions with\nneighbouring PVA chains. Thus I would expect that 4PACz would exhibit similar total\ninteraction energy as 2PACz.\nAuthor reply: We really appreciate the professional comments. The geometry and\nspatial orientation of chromophores (2PACz and 4PACz) relative to the PVA chain\nwere carefully optimized following established protocols reported in recent\nliterature (Nat. Commun. 2024, 15, 7605; Angew. Chem. Int. Ed. 2025, 64, e202507273;\nAngew. Chem. Int. Ed. 2025, 64, e202505876). The optimized structures obtained in\nour work are similar to the references. 2PACz exhibits a bent conformation\nbetween the carbazole unit and the phosphonic acid alkyl chain, whereas 4PACz\nadopts a more linear arrangement.\nTo realistically simulate the binding mode within the PVA film, we model the\nPVA chain as an oligomer of eight repeating units, in line with previous reports\n(Angew. Chem. Int. Ed. 2025, 64, e202509506; Angew. Chem. Int. Ed. 2024, 63,\ne202403773). During geometry optimization, the most electronegative site of the\nPVA chain is paired with the most electropositive site of the chromophore to ensure\na physically meaningful interaction profile. Our optimized structures in multiple\nPVA chain environments show that 2PACz retains an alkyl chain oriented nearly\nperpendicular to the carbazole plane, enabling additional non-classical interactions\n(C–H···C(π) and O–H···C(π)) with the π-system. This bent geometry promotes a\ndenser and more rigid hydrogen bond network with PVA. In contrast, the longer\nand more flexible alkyl chain in 4PACz leads to a predominantly linear conformation,\nwhich reduces the opportunity for such additional contacts and results in a more\ndynamic, less robust binding interaction with PVA. Moreover, both 2PACz and\n4PACz reveal increased binding energies when the PVA chain increases from single\nto two and three (Supplementary Figure 53). Notably, the binding energies of\n2PACz/PVA system are always higher than those of 4PACz/PVA system. These\nstructural and electronic differences explain the distinct binding energies observed\nbetween the two systems. We have added the additional theoretical calculations\nand explanation into the revised manuscript.\nUpdated figure:\nSupplementary Figure 53. Theoretical calculated binding energies of 2PACz (a, d,\ng), 2CACz (b, e, h) and 4PACz (c, f, i) with one (a-c), two (d-f) and three (g-i) PVA\nchains. Note: For the NCI, red represents repulsive interactions, green represents\nvan der Waals interactions, and blue represents attractive interactions.\n4.2 I additionally suggest improving this section by comparing partial atomic charges\nor total group charges (e.g., for the carbazole unit) for single molecules of 2PACz,\n4PACz, and 2CACz.\nAuthor reply: We appreciate the reviewer's insightful comment. As suggested, we\ncalculated the electrostatic potential (ESP) of the carbazole units in 2PACz,\n4PACz, and 2CACz to evaluate how the anchor group and alkyl chain length influence the\ninteraction with the PVA. The results (Supplementary Fig. 50 and Table 3)\ndemonstrate that the carbazole in 2PACz has a higher ESP than that in 2CACz.\nFurthermore, the longer alkyl chain in 4PACz attenuates the electron-withdrawing\neffect of anchoring groups, leading to a lower ESP on its carbazole unit.\nConsequently, the higher ESP of the carbazole unit in 2PACz thus confers its\nstrongest binding energy with PVA (Supplementary Fig. 51). 2PACz@PVA exhibits\nthe binding energies of −282.65 kcal mol⁻¹, significantly exceeding those of\n4PACz@PVA (−220.83 kcal mol⁻¹) and 2CACz@PVA (−191.27 kcal mol⁻¹). This trend\ndirectly correlates with the binding energies between the chromophores (2PACz,\n4PACz, and 2CACz) and PVA. We hope our added theoretical calculations can\naddress the reviewer’s concerns. We have updated the discussion in the revised\nmanuscript and Supplementary Information. Many thanks.\nAdded text: The higher electrostatic potential (ESP) of the carbazole unit in 2PACz,\ncompared to those in 4PACz and 2CACz, corresponds to its stronger computed\nbinding energy with PVA (–282.65 kcal mol-1) (Supplementary Figs. 50, 51 and Table\n3).\nUpdated table:\nSupplementary Table 3. The ESP on the local van der Waals surface of 2PACz, 4PACz\nand 2CACz.\n2PACz 4PACz 2CACz\nOxygen in P=O/C=O -31.44 kcal mol-1 -30.03 kcal mol-1 -19.52 kcal mol-1\nOxygen in hydroxyl -12.41 kcal mol-1 -9.84 kcal mol-1 -2.93 kcal mol-1\nHydrogen in hydroxyl 28.71 kcal mol-1 27.43 kcal mol-1 28.14 kcal mol-1\nPhosphonic acid groups 21.99 kcal mol-1 9.81 kcal mol-1 -\nCarboxyl groups - - 17.51 kcal mol-1\nCarbazole groups -151.13 kcal mol-1 -139.98 kcal mol-1 -133.75 kcal mol-1\nAdded figure：\nSupplementary Figure 51. Theoretical calculated binding energies between\ncarbazole and PVA in 2PACz@PVA (a), 4PACz@PVA (b) and 2CACz@PVA (c). Note:\nFor the non-covalent interaction index (NCI), red represents repulsive interactions,\ngreen represents van der Waals interactions, and blue represents attractive\ninteractions.\n5.1 The polarizer typically reduces transmitted light. Quantum yield values should be\nprovided for the final materials coated with PLA polarizer.\nAuthor reply: We appreciate the constructive suggestions. Compared to the pure\nluminescent films, the stacked films coated with PLA polarizer show slightly\ndecreased PLQYs. The updated result has been added into the revised manuscript.\nAdded text: Compared to the pure luminescent films, the stacked films coated with\nPLA polarizer show slightly decreased PLQYs (Supplementary Table 6).\nAdded table:\nSupplementary Table 6. The PLQY of stacked films with and without PLA films.\n2PACz@PVA Fluc@2PACz@PVA Rh123@2PACz@PVA Rh6G@2PACz@PVA\nWithout PLA 33.3% 33.8% 12.5% 26.6%\nWith D-PLA 21.2% 23.3% 10.1% 19.8%\nWith L-PLA 23.0% 21.1% 8.5% 18.6%\n5.2 In addition, it is not clear why some PLQY values for dye-doped 2PACz@PVA are\nsimilar (or even higher) that the value for the non-dye doped 2PACz@PVA (Table S3,\nlast column), which is slightly unexpected considering the efficiency of FRET.\nAuthor reply: Thanks for the reviewer's professional question. This improvement\narises from a fast radiative decay rate of the acceptor, which provides a highly\nradiative pathway for donor excitons upon efficient energy transfer from the donor\nto the acceptor. As a result, non‑radiative losses in the donor are substantially\nreduced, leading to an increase in the total emission efficiency. Therefore, a net\nenhancement of PLQYs following FRET is indeed possible, as also supported by\nearlier reports (J. Fluoresc. 2002, 12, 97). In our work, the selected guests (Fluc,\nRh123, and Rh6G) have a high PLQY up to ~100.0%, whereas the SSPL of host 2PACz\nis relatively weak owing to the non-radiative decay of the excitons. By taking\nadvantage of efficient energy transfer from 2PACz/PVA to the guests and highly\nefficient radiative transitions of fluorescence guests, the non-radiative\ndepopulation of excitons of the donor is significantly decreased, leading to the\nincreased quantum yields of the resulting doped systems. In fact, the improvement\nof quantum yields after the FRET process is widely observed in host-guest systems\nin previous works (Table R1).\nTable R1. Summary of PLQYs before and after the FRET process in previous works.\nReference PLQYs PLQYs after FRET\nNat. Commun. 2014, 5, 4016. 57% 88%\nChem. Eur. J. 2017, 24, 1151. 33% 37%\nAdv. Mater. 2018, 30, 1800365. 13% 46%\nAngew. Chem. Int. Ed. 2020, 59, 9393. 25.6% 53.8%\nNat. Photonics. 2021, 15, 203. 86% 97%\nSci. Adv. 2022, 8, eabk2925 20.7% 36.0%\nNat. Commun. 2024, 15, 3053. 26.4% 37.3%\n6. The synthesis and characterization of the studied compounds should be\nsupplemented with additional information:\na) Please provide the information on reaction yields.\nAuthor reply: We really appreciate the professional suggestion. We have added the\nyields in the revised Supplementary Information.\nb) 1H, 13C NMR and HR-MS spectra should be provided for all new compound including\nintermediate compounds. In case the compound is already known in the literature, its\nstructure should be confirmed by 1H NMR analysis. The literature citation to the\nexisted procedure should be provided. If the currently used procedures are not\nidentical with the literature ones, full description should be provided along with the\n1H and 13C NMR data. Copies of all NMR and HRMS spectra should be supplemented in\nSI.\nAuthor reply: Thanks for the professional suggestions. The 1H NMR, 13C NMR and\nhigh-resolution mass spectrometry (HR-MS) spectra of all compounds have been\nprovided in the Supplementary Information.\nAdded figures:\nSupplementary Figure 1. 1H nuclear magnetic resonance (NMR) spectrum of Cz-2-\nBr.\nSupplementary Figure 2. 13C NMR spectrum of Cz-2-Br.\nSupplementary Figure 3. High-resolution mass spectrometry (HR-MS) of Cz-2-Br.\nSupplementary Figure 4. 1H NMR spectrum of PAO-2-Cz.\nSupplementary Figure 5. 13C NMR spectrum of PAO-2-Cz.\nSupplementary Figure 6. HR-MS of PAO-2-Cz.\nSupplementary Figure 9. HR-MS of 2PACz.\nSupplementary Figure 11. 1H NMR spectrum of Cz-4-Br.\nSupplementary Figure 12. 13C NMR spectrum of Cz-4-Br.\nSupplementary Figure 13. HR-MS of Cz-4-Br.\nSupplementary Figure 14. 1H NMR spectrum of PAO-4-Cz.\nSupplementary Figure 15. 13C NMR spectrum of PAO-4-Cz.\nSupplementary Figure 16. HR-MS of PAO-4-Cz.\nSupplementary Figure 19. HR-MS of 4PACz.\nSupplementary Figure 21. 1H NMR spectrum of Me-3-Cz.\nSupplementary Figure 22. 13C NMR spectrum of Me-3-Cz.\nSupplementary Figure 23. HR-MS of Me-3-Cz.\nSupplementary Figure 26. HR-MS of 2CACz.\nMinor issues:\n1. Main article:\na) Page 2: Synthesis and characterization: 2PACz and 4PACz were obtained in three\nsteps.\nAuthor reply: We are very sorry for the mistake. We have corrected the description\nregarding the synthesis steps and have carefully reviewed the entire manuscript to\nensure consistency and accuracy throughout.\nb) Figure 1c. The drawing is not clear and lack of consistency with the procedure\npresented in SI and Scheme S3.\nAuthor reply: We appreciate the professional comments. The drawing of Figure 1c.\nhas been revised to maintain consistency with Supplementary Scheme 3.\nUpdated figure:\nFig. 1 | Schematic diagram for constructing multi-color chiral organic afterglow\n(COA) by hydrogen bond mediation and phosphorescence energy transfer. a\nPrinciple drawing for hydrogen bond strength mediation through modulating\nelectronegativity of hydrogen bond acceptor and spatial arrangement of hydrogen\nbond. b Formation of a three-dimensional hydrogen bond network mediated by\nphosphorus in polyvinyl alcohol (PVA) film and the molecular structure of 2PACz\nand PVA. c Preparation procedure and corresponding afterglow photographs of\nmulti-color COA films, as well as the molecular structures of the incorporated multi-\ncolor fluorescence emitters.\nc) Figure 2d: The quality factor is not defined.\nAuthor reply: Thanks for the useful suggestion. An operational figure of merit is\ndefined as 𝑄\nFM\n=PLQY×𝜏 A, where PLQY is the photoluminescent quantum yield and\n𝜏 A is the afterglow lifetime. We have updated Figure 2d in the revised manuscript.\nAdded text: Consequently, 0.5 wt.% 2PACz@PVA film demonstrates the best figure\nof merit, defined as 𝑄 FM =PLQY×𝜏 A (Fig. 2d and Supplementary Table 1).\nUpdated figure:\nFig. 2 | The figure of merit (d) of 2PACz@PVA films at different doping\nconcentrations.\nd) Page 3: afterglow mechanism analysis: The quantum yields and afterglow lifetimes\nfor 4PACz and 2CACz at the optimal concentrations in PVA should be provided in the\nmain text aside the values discussed for 2PACz.\nAuthor reply: We really appreciate the professional comments. We have updated\nthe discussion and Figure 3 in the revised manuscript.\nUpdated text: Specifically, the 0.5 wt.% 4PACz and 2CACz doped PVA films show\nlifetimes of 2.84 s and 2.65 s as well as PLQYs of 30.3% and 30.1% (Fig. 3b and\nSupplementary Fig. 35b).\nUpdated figure:\nFig. 3 | Intermolecular interaction investigations. a SSPL (dashed line) and delayed\nPL (solid line) spectra of 4PACz@PVA and 2CACz@PVA films with 0.5 wt.% doping\nconcentrations; b Lifetime, photoluminescence quantum yield (PLQY) of 0.5 wt.%\n4PACz@PVA and 0.5 wt.% 2CACz@PVA films.\ne) Page 3: afterglow mechanism analysis: “2PACz@PVA film exhibits much enhanced\nafterglow intensities and lifetimes than those of 4PACz and 2CACz doped PVA films,\nwhich may be due to the additional n-π* transition contribution of oxygen atom in\nP=O in the frontier molecular orbital distributions of 2PACz, thus enabling much larger\nspin orbit coupling constants of 2PACz than that of 4PACz and 2CACz”. However, from\nFigure S13 it seems that the contribution of the P=O oxygen atom to the HOMO is\ninsignificant. In addition, the S1-Tn SOC values (Figure S14) are generally higher for\n2CACz than for 2PACz. It should be noted that in 2PACz and 4PACz, two carbon atoms\nfrom the alkyl chain contribute to the HOMO, while in 2CACz, the distribution also\nextends over the carboxylic group.\nAuthor reply: We really appreciate the reviewer’s valuable and insightful\ncomments. We are very sorry for the description that “thus enabling much larger\nspin orbit coupling constants of 2PACz than that of 4PACz and 2CACz”. As shown\nin Supplementary Figure 37, the difference of S-T SOC values in 2PACz, 4PACz and\n1 n\n2CACz is limited. In contrast, the T-S SOC value of 2PACz (0.125) is much higher\n1 0\nthan that of 4PACz (0.030) and 2CACz (0.035). Therefore, the description should be\nthat “thus enabling a much larger spin orbit coupling constant of T-S of 2PACz\n1 0\nthan that of 4PACz and 2CACz”. According to El-Sayed’s rule, compared to the\nfrontier molecular orbital distribution on the alkyl chain, the n–π* transitions play\na much-enhanced role in boosting the ISC process. The calculations reveal a higher\nn-electron contribution in 2PACz than that in 4PAC and 2CACz, which likely accounts\nfor its larger SOC value (Supplementary Figure 36). We hope this explanation\nsatisfactorily addresses the reviewer’s concerns. We have rewritten the related\ndescriptions. Many thanks.\nUpdated text: This enhanced performance can be attributed to the additional n-π*\ntransition contribution by the oxygen atom in P=O in the frontier molecular orbital\ndistributions of 2PACz (Supplementary Fig. 36), thus enabling a much larger spin\norbit coupling constant of T-S of 2PACz than that of 4PACz and 2CACz\n1 0\n(Supplementary Fig. 37).\nUpdated figure:\nSupplementary Figure 36. Theoretically calculated frontier molecular orbitals\ndistributions of 2PACz (red circle: n-* transition position), 4PACz and 2CACz.\nHOMO and LUMO are the highest occupied molecular orbital and the lowest\nunoccupied molecular orbital, respectively.\nf) Page 4: “The stronger electron-donating ability of the phosphorus atom in the\nphosphate group results in a higher negative charge density on the oxygen atom in\nP=O and O-H of 2PACz compared to the oxygen atom in C=O and O-H of 2CACz”. It is\nmore convenient to discuss differences between -P(O)(OH)2 and COOH groups in\nterms of the lower electronegativity of phosphorus and the more polar nature of P=O\n/ P-OH bond compared to C=O / C-OH.\nAuthor reply: We thank the reviewer for the careful review and constructive\nsuggestions. In response, we have expanded the discussion beyond individual\natoms to include a comparative analysis of the –P(O)(OH) and –COOH anchoring\n2\ngroups. As shown by ESP analysis, the phosphonic acid group in 2PACz exhibits a\nsubstantially more positive ESP profile than the carboxyl group in 2CACz\n(Supplementary Figure 50 and Table 3). This stronger positive ESP promotes\nenhanced binding interactions between the phosphonic acid group and the\nhydroxyl-rich PVA matrix, leading to a higher binding energy compared to that of\nthe carboxyl-containing system (Supplementary Figure 52). The corresponding\ndiscussion has been added to the revised manuscript to clarify these points.\nAdded text: Furthermore, the phosphonic acid reveals more positive ESP values in\n2PACz compared to the carboxyl group in 2CACz, which confers a higher binding\nenergy between phosphonic acid and PVA (Supplementary Figs. 50, 52 and Table 3).\nAdded figure:\nSupplementary Figure 52. Theoretical calculated binding energies between the\nphosphonic acid group of 2PACz and PVA (a) and carboxyl group of 2CACz and PVA\n(b). Note: For the NCI, red represents repulsive interactions, green represents van\nder Waals interactions, and blue represents attractive interactions.\nAdded table:\nSupplementary Table 3. The ESP on the local van der Waals surface of 2PACz, 4PACz\nand 2CACz.\n2PACz 4PACz 2CACz\nOxygen in P=O/C=O -31.44 kcal mol-1 -30.03 kcal mol-1 -19.52 kcal mol-1\nOxygen in hydroxyl -12.41 kcal mol-1 -9.84 kcal mol-1 -2.93 kcal mol-1\nHydrogen in hydroxyl 28.71 kcal mol-1 27.43 kcal mol-1 28.14 kcal mol-1\nPhosphonic acid groups 21.99 kcal mol-1 9.81 kcal mol-1 -\nCarboxyl groups - - 17.51 kcal mol-1\nCarbazole groups -151.13 kcal mol-1 -139.98 kcal mol-1 -133.75 kcal mol-1\n2. Supporting Information:\na) Figures S1 and S3: It seems that the phase correction should be performed.\nAuthor reply: We really appreciate the professional suggestion. We have modified\nthe 1H NMR in the revised Supplementary Information.\nb) Figure S7. Please indicate the excitation wavelength and concentration of the\ncompound.\nAuthor reply: We appreciate the professional comments and thoughtful\nsuggestions. We have indicated the excitation wavelength and concentration of\nthe compound in Supplementary Figure 30 in the revised Supplementary\nInformation.\nc) Figure S19. The figure caption should describe all shapes presented, including those\npresumably visualizing non-covalent interaction index (NCI).\nAuthor reply: Thanks for the reviewer's professional suggestions. The figure\ncaption in Supplementary Figure 51 has been updated. The red represents repulsive\ninteractions, green represents van der Waals interactions, and blue represents\nattractive interactions.\nd) Please indicate the eluent in chromatography purification procedures. Please\nindicate the solvent used in the recrystallization of 2PACz and Cz-2-Br.\nAuthor reply: We appreciate the constructive suggestions. We have added the\neluent in chromatography purification procedures and the solvent used in the\nrecrystallization of 2PACz and Cz-2-Br in the revised Supplementary Information.\ne) It would be beneficial if authors provide the 31P NMR spectra for 2PACz and 4PACz.\nAuthor reply: We appreciate the constructive suggestions. We have added the 31P\nNMR spectra for 2PACz and 4PACz in the revised Supplementary Information. Many\nthanks.\nAdded figures:\nSupplementary Figure 10. 31P NMR spectrum of 2PACz.\nSupplementary Figure 20. 31P NMR spectrum of 4PACz.\nf) The chemical shifts for 13C NMR should be given to the first decimal place.\nAuthor reply: We sincerely appreciate the reviewer's professional comment. We\nhave updated the chemical shifts for 1H and 13C NMR spectra in the revised\nSupplementary Information. Many thanks.\ng) Table S3: PLQY values should be given to the first decimal place.\nAuthor reply: Thanks for the reviewer's professional suggestion. We have updated\nthe decimal place of PLQY values in Supplementary Table 4. Many thanks.\nh) Metling temperature should be specified for all solid compounds.\nAuthor reply: We really appreciate the professional and insightful suggestion. As\nsuggested, the melting temperatures (T ) of the solid compounds 2PACz, 4PACz,\nm\nand 2CACz were determined by differential scanning calorimetry. The melting\npoints are identified as 240°C, 285°C, and 175°C for 2PACZ, 4PACZ, and 2CACZ,\nrespectively (Supplementary Figure 27). We have added the melting temperatures\nin the revised Supplementary Information and manuscript.\nAdded text: The melting temperatures of 2PACz, 4PACz, and 2CACz are 240°C, 285°C,\nand 175°C, respectively (Supplementary Fig. 27).\nAdded figure:\nSupplementary Figure 27. The differential scanning calorimetry curves of 2PACz\n(a), 4PACz (b) and 2CACz (c).\ni) The energy values for HOMO and LUMO levels should be provided.\nAuthor reply: We sincerely thank the reviewer for this nice suggestion. HOMO and\nLUMO energy levels of 2PACz, 4PACz, and 2CACz have updated in the revised\nSupplementary Information. Many thanks.\nReviewer #2:\nComment: The manuscript presents a novel approach for enhancing chiral organic\nafterglow (COA) materials by leveraging phosphine-mediated hydrogen bonds, which\nsignificantly improve afterglow emission and thermal stability. The use of energy\ntransfer mechanisms facilitates the development of multicolor afterglow emissions,\nmaking the material highly suitable for applications in anti-counterfeiting and\nencryption. Given the novelty and broad interest of this work, I recommend its\nacceptance in Nature Communications as it provides valuable insights into the field of\nCOA materials. Although the study is well-investigated and organized, based on\nsystematic theoretical and experimental results, a few minor revisions are\nrecommended:\nAuthor reply: Thanks for the professional comments and recommendation of our\nwork. We have carefully addressed the points raised by the reviewer.\n1. The abbreviation \"m-\" in Supplementary Figure S11 typically represents the meta\nposition in organic chemistry. The corresponding methyl abbreviation should be\nmodified to \"Me-\".\nAuthor reply: We really appreciate the professional comments. We have changed\n“m-” to “Me-” in the revised Supplementary Information.\n2. Can long-lived afterglow emission be achieved by directly exciting the doped\nfluorescence dyes?\nAuthor reply: Thanks for the reviewer’s professional question. Despite the\nconfinement interaction of the hydrogen bond provided by the PVA matrix, no\nobvious long-lived afterglow emission can be found in Fluc@2PACz@PVA,\nRh123@2PACz@PVA, and Rh6G@2PACz@PVA doped films (Supplementary\nFigure 67). This result provides direct evidence that the implementation of a FRET\nstrategy is essential for achieving long-lived and highly efficient afterglow emission.\nAdded text: Fluc@2PACz@PVA, Rh123@2PACz@PVA, and Rh6G@2PACz@PVA\ndoped films exhibit no detectable long-lived afterglow when the fluorescent dyes\nare directly excited (Supplementary Fig. 67).\nAdded figure:\nSupplementary Figure 67. Delayed PL spectra of Fluc@2PACz@PVA (a),\nRh123@2PACz@PVA (b), and Rh6G@2PACz@PVA (c) films.\n3. The long-term stability of the hydrogen bonds and their performance under\ndifferent environmental conditions (e.g., temperature variation, humidity) need\nfurther exploration.\nAuthor reply: We appreciate the constructive suggestions raised by the reviewer.\nTo investigate the long-term stability of hydrogen bond and afterglow properties\nof 2PACz@PVA film, we measured the SSPL and delayed PL spectra under different\ntemperatures and humidity. As shown in Supplementary Figure 40, the afterglow\nspectra keep almost unchanged when the sample is placed at 77 K, 298 K and 343\nK for different times, respectively. These results suggest the excellent stabilities of\nhydrogen bonds and afterglow emissions at different temperatures. Moreover,\nwhen the samples are placed at a relative humidity of 25%, the afterglow emissions\nalso remain unchanged with the increasing storage times, demonstrating good\nstability at low humidity; in contrast, when the relative humidity increases to 90%,\nthe afterglow intensities are largely decreased with the increasing storage times\nbecause of the disruption of the hydrogen bond network within the 2PACz@PVA\nfilm by water molecules (Supplementary Figure 41). This disruption compromises\nthe ability of the PVA matrix to suppress molecular vibrations, thereby leading to\nthe quenching of triplet excitons. The added experiments and discussions have\nbeen added in the revised manuscript and Supplementary Information. Many\nthanks.\nAdded text: Furthermore, 0.5 wt.% 2PACz@PVA film exhibit stable afterglow at\nvarious temperatures (77-343 K) (Supplementary Fig. 40). The afterglow intensity\nremains constant over time at 25% relative humidity, whereas at 90% humidity,\nmoisture disrupts the hydrogen bond network in the film. This leads to the\nenhanced molecular vibrations and triplet excitons quenching, which significantly\nreduces afterglow intensity (Supplementary Fig. 41).\nAdded figures:\nSupplementary Figure 40. Delayed PL spectra of 0.5 wt.% 2PACz@PVA film\nmeasured after being stored at 77 K (a), 298 K (b) and 343 K (c) for various durations.\nSupplementary Figure 41. Delayed PL spectra of 0.5 wt.% 2PACz@PVA measured\nunder 25% (a) and 90% (b) relative humidity over different time periods.\n4. The role of the interfacial chiral polylactic acid (PLA) layer in maintaining chiral\namplification and enhancing the material's afterglow efficiency is intriguing, but\nadditional details on its impact under various conditions would be beneficial.\nAuthor reply: We appreciate the reviewer’s insightful comment on the interfacial\nchiral PLA layer. To further clarify its behavior under different conditions, we\nperformed a series of control experiments examining chirality and afterglow\nstability under varying humidity, temperature, and continuous UV excitation. As\nshown in Supplementary Figure 76, the CPL intensities of both 2PACz@PVA@D-\nPLA and 2PACz@PVA@L-PLA films increase notably as temperature decreases,\nwhich can be attributed to suppressed exciton thermal quenching at lower\ntemperatures. In contrast, after exposure to a high-humidity environment (80°C\nwater vapor), both CPL and afterglow emissions decrease considerably\n(Supplementary Figure 74). Furthermore, under continuous 365 nm irradiation at a\npower of 100 W for 4 h, the afterglow intensity retains about 77 % of its initial value,\nwhich demonstrates a good photostability (Supplementary Figure 75), providing a\nmore comprehensive understanding of the PLA interfacial layer’s impact. Thanks\nagain.\nAdded text: Exposure to high humidity substantially (Supplementary Fig. 74)\nreduces afterglow emissions. After 4 h of 365 nm irradiation, the afterglow retains\n~77% intensity (Supplementary Fig. 75). Due to suppressed exciton thermal\nquenching (Supplementary Fig. 76), decreased temperature significantly enhances\nthe CPL intensity.\nAdded figures:\nSupplementary Figure 74. CPL spectra of 0.5 wt.% 2PACz@PVA@D-PLA and\n2PACz@PVA@L-PLA films under water fumigation at 80°C with different times.\nSupplementary Figure 75. CPL spectra of 0.5 wt.% 2PACz@PVA@D-PLA and\n2PACz@PVA@L-PLA films before and after irradiation by 365 nm UV light for 4 h.\nSupplementary Figure 76. Temperature-dependent CPL spectra of 0.5 wt.%\n2PACz@PVA@D/L-PLA films.\n5. While the manuscript is well-organized and the experimental data are robust, some\nminor grammatical revisions are needed to enhance clarity and readability.\nAuthor reply: We appreciate the constructive suggestions raised by the reviewer.\nWe have revised the grammatical mistakes carefully and conscientiously.\n6. Can chiral afterglow emission be achieved by directly doping 2PACz@PVA into the\nPLA matrix?\nAuthor reply: We appreciate the professional comments and thoughtful\nsuggestions. As shown in Supplementary Figure 71, the chiral afterglow emission\ncan be achieved in 2PACz@PVA doped PLA films, but the CPL intensities are much\nsmaller than the corresponding 2PACz@PVA@D-PLA and 2PACz@PVA@L-PLA\nstacked polymer films, suggesting the superior afterglow properties of stacked\nfilms. We have added the results in the revised manuscript and Supplementary\nInformation. Many thanks.\nAdded text: The stacked films show much improved CPL performance than that of\nfilms prepared via direct doping of 2PACz@PVA into the PLA matrix\n(Supplementary Fig. 71).\nAdded figure:\nSupplementary Figure 71. CPL spectra of the films by directly doping 2PACz@PVA\ninto the PLA matrix.\nThe details of the changes made are shown as follows.\n(1) The NMR and HR-MS spectra of all materials have been added and updated\n(Supplementary Figure 1-26).\n(2) The differential scanning calorimetry curves of 2PACz, 4PACz and 2CACz have\nbeen added (Supplementary Figure 27).\n(3) The figure 1c and figure 3 have been updated.\n(4) The thermogravimetric analysis curves of 0.5 wt.% 2PACz@PVA, 4PACz@PVA,\nand 2CACz@PVA films have been added (Supplementary Figure 28).\n(5) The 1H NMR spectrum of 0.5 wt.% 2PACz@PVA in D O have been added\n2\n(Supplementary Figure 29).\n(6) The theoretically calculated frontier molecular orbitals distributions of 2PACz,\n4PACz and 2CACz have been updated (Supplementary Figure 36).\n(7) The figure of merits of 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films have\nbeen added (Supplementary Figure 38).\n(8) The delayed PL spectra of 0.5 wt.% 2PACz@PVA film measured after being\nstored at 77 K, 298 K and 343 K for various durations have been added\n(Supplementary Figure 40).\n(9) The delayed PL spectra of 0.5 wt.% 2PACz@PVA film measured under 25%, and\n90% relative humidity over different time periods have been added (Supplementary\nFigure 41).\n(10) The 2D-wide angle X-ray scattering (WAXS) pattern and WAXS spectrum of\n2PACz@PVA film have been added (Supplementary Figure 43).\n(11) The energy dispersive X-ray spectroscopy and elemental mapping images of 0.5\nwt.% 2PACz@PVA film have been added (Supplementary Figure 44).\n(12) The SSPL spectra of multiple independently prepared batches of 0.5 wt.%\n2PACz@PVA, 0.5 wt.% 4PACz@PVA and 0.5 wt.% 2CACz@PVA films have been\nadded (Supplementary Figure 45).\n(13) The normalized Fourier transform infrared and Raman spectra of PVA, 0.5 wt.%\n2PACz@PVA, 0.5 wt.% 4PACz@PVA and 0.5 wt.% 2CACz@PVA films have been\nadded (Supplementary Figure 47).\n(14) The SSPL spectra of 2PACz@PS, 4PACz@PS and 2CACz@PS at a 1:200 mass\nratio has been added (Supplementary Figure 48).\n(15) The SSPL and delayed PL spectra of 2PACz doped in different polymer matrices\nat a 1:200 mass ratio have been added (Supplementary Figure 49).\n(16) The theoretical calculated binding energies between carbazole and PVA in\n2PACz@PVA, 4PACz@PVA and 2CACz@PVA have been added (Supplementary\nFigure 51).\n(17) The theoretical calculated binding energies between the phosphonic acid\ngroup of 2PACz and PVA and carboxyl group of 2CACz and PVA have been added\n(Supplementary Figure 52).\n(18) The theoretical calculated binding energies of 2PACz, 2CACz and 4PACz with\none, two and three PVA chains have been updated (Supplementary Figure 53).\n(19) The directly excited fluorescent dyes delayed PL spectra of Fluc@2PACz@PVA,\nRh123@2PACz@PVA, and Rh6G@2PACz@PVA films have been added\n(Supplementary Figure 67).\n(20) The CPL spectra of the films by directly doping 2PACz@PVA into the PLA matrix\nhave been added (Supplementary Figure 71).\n(21) The CPL spectra of 0.5 wt.% 2PACz@PVA@D-PLA and 2PACz@PVA@L-PLA\nfilms under water fumigation at 80°C with different times have been added\n(Supplementary Figure 74).\n(22) The CPL spectra of 0.5 wt.% 2PACz@PVA@D-PLA and 2PACz@PVA@L-PLA\nfilms before and after irradiation by 365 nm UV light for 4h have been added\n(Supplementary Figure 75).\n(23) The temperature-dependent CPL spectra of 0.5 wt.% 2PACz@PVA@D-PLA and\n2PACz@PVA@L-PLA films have been added (Supplementary Figure 76).\n(24) The CPL spectra of 2PACz@PVA@D/L-PLA, 4PACz@PVA@D/L-PLA and\n2CACz@PVA@D/L-PLA at varied temperatures have been added (Supplementary\nFigure 77).\n(25) The afterglow quantum yields (QYs) for multiple independently prepared\nbatches of 2PACz@PVA, 4PACz@PVA and 2CACz@PVA films have been added\n(Supplementary Table 2).\n(26) The theoretical calculated ESP on the local van der Waals surface of 2PACz,\n4PACz and 2CACz have been updated (Supplementary Table 3).\n(27) The summary of the afterglow lifetimes and dissymmetry factors (g ) of\nlum\nCPOA materials in recently reported works has been added (Supplementary Table\n5).\n(28) The PLQYs of stacked films with and without PLA films have been added\n(Supplementary Table 6).\n(29) The information on reaction yields and the details of synthesis have been\nrevised.\n(30) Some unclear descriptions have been revised.\n(31) The numbers assigned to the figures and references have been updated."}, {"round": 2, "reviewer_comments": {"reviewer_1": "I have carefully read the resubmitted manuscript together with the answers provided for my and second Reviewer comments.\nI have to admit that the authors have addressed all of my concerns and they have done impressive work to improve their\nmanuscript. While I initially had reservations about the novelty of the original submission, upon further review, I believe that\nthe revised manuscript is suitable for publication in the Nature Communications. I have no additional comments or remarks.", "reviewer_2": "All points raised in my initial review have been addressed satisfactorily by the authors.\nThe newly added experiments and theoretical discussions have considerably\nstrengthened the manuscript's insights into the supramolecular engineering of\ndirectional hydrogen bond networks derived from phosphonic acids functional group.\nConsequently, I am pleased to support the publication of this work in Nature\nCommunications."}, "author_response": "Reviewer #1:\nI have carefully read the resubmitted manuscript together with the answers provided\nfor my and second Reviewer comments. I have to admit that the authors have\naddressed all of my concerns and they have done impressive work to improve their\nmanuscript. While I initially had reservations about the novelty of the original\nsubmission, upon further review, I believe that the revised manuscript is suitable for\npublication in the Nature Communications. I have no additional comments or remarks.\nAuthor reply: We appreciate the reviewer’s acceptance and recommendation of\nour work!\nReviewer #2:\nAll points raised in my initial review have been addressed satisfactorily by the authors.\nThe newly added experiments and theoretical discussions have considerably\nstrengthened the manuscript's insights into the supramolecular engineering of\ndirectional hydrogen bond networks derived from phosphonic acids functional group.\nConsequently, I am pleased to support the publication of this work in Nature\nCommunications.\nAuthor reply: We are very grateful for the recommendation!"}]

Decision letter