DOI: 10.5281/zenodo.13924113
title: Photophysical and Spectroscopic dataset for Carrier Dynamics and Recombination in Ag-In-Zn-S Quantum Dots

description: (1) HR-TEM images of alloyed AgIn1.5Zn1.9S3.6 (A1) and AgIn1.5Zn4.4S6.8 (A2) nanocrystals.

(2) Energy-dispersive spectra of alloyed AgIn1.5Zn1.9S3.6 (A1) and AgIn1.5Zn4.4S6.8 (A2) nanocrystals.

(3) UV-vis-NIR spectra of A1 nanocrystals and A1-MV, where the nanocrystals are conjugated with methyl viologen (MV2+) molecules.

(4) (a) Normalized PL decays of A1 nanocrystals measured at various detection wavelengths, (b and c) PL decays measured at room temperature for A1 and A2 nanocrystals, (d and e) PL decays measured at various temperatures for A1 and A2 nanocrystals.

(5) Transient absorption (TA) spectra for A1 nanocrystals for various pump-probe delays.

 

This work was supported by National Science Centre Poland Grant No. 2019/35/B/ST3/04235.

P.K., P.B., and A.P. acknowledge the financial support from the National Science Centre of Poland, Grant No. 2022/45/B/ST5/02120.
description: (1) High-resolution images were acquired by a Tecnai TF20 X-TWIN (Thermo Fisher Scientific) microscope operated at 200 kV.

(2) Elemental analysis of alloyed Ag-In-Zn-S nanocrystals was carried out with a multichannel Quantax 400 energy-dispersive X-ray spectroscopy (EDS) system with a 125 eV xFlash detector 5010 (Bruker) using a 15 kV electron beam energy.

(3) The absorption spectra were measured using the Agilent Varian Cary 50 UV-visible spectrophotometer.

(4) The photoluminescence (PL) measurements were performed in a custom-built setup using a pulsed laser emitting at 405 nm (Picoquant P-C-405B) as the excitation source. The PL signal was measured using an Andor Newton Du-920P CCD camera coupled with an Andor Kymera 328i monochromator.

(5) The transient absorption (TA) experiments were carried out on nanocrystals dispersed in chloroform. The nanocrystals were carried with 100 fs pump laser pulse at 400 nm with excitation densities ranging from 63 to 1840 mJ/cm2.
description: MaterialsSilver nitrate (99%), indium(II) chloride (99%), zinc stearate (technical grade), 1-dodecanethiol(DDT, 98%), sulfur (99%), 1-octadecene (ODE, 90%), oleylamine (OLA, 70%), methyl viologendichloride hydrate, 98% were supplied by Sigma-Aldrich (Merck KGaA, Darmstadt,Germany).

Synthesis of Ag-In-Zn-S Quantum DotsAll operations were carried out under a constant dry argon flow. Silver nitrate (0.03 g, 0.18 mmol), indium(II) chloride (0.11 g, 0.59 mmol), DDT (0.20 g, 1.0 mmol), and zinc stearate (0.33 g, 0.54 mmol for A1 or 0.66 g, 1.08 mmol for A2) were mixed with ODE (15 mL) in a three-neck flask. The mixture was heated to 150 °C until a homogeneous solution was formed. Then, 1 mL of the S/OLA precursor was quickly injected into the reaction solution. The temperature was increased to 180 °C, and the mixture was kept at this temperature for 60 min. After the mixture was cooled to room temperature, toluene (10 mL) was added, and the reaction mixture was centrifuged; the isolated black precipitate consisting of organic waste and agglomerated particles was separated. The supernatant was treated with 30 mL of acetone, leading to the precipitation of the desired fraction of quantum dots. The quantum dots were separated by centrifugation (7000 rpm, 5 min) and then redispersed in nonpolar solvents such as toluene, dichloromethane, chloroform.

Conjugating Ag-In-Zn-S Quantum Dots with Methyl Viologen15 μl of MV^2+ solution (∼230 mg of MV^2+ in 1 ml of methanol) was added to 200 μl of concentrated Ag-In-Zn-S chloroform solution. The sample became cloudy, which wasattributed to an excess of undissolved MV^2+. The solution was sonicated, evaporated and redissolved in 200 μl of chloroform. The resulting solution was passed through a syringe filter with a pore size of 0.22 μm. As a result, a clear solution of Ag-In-Zn-S QDs with adsorbedMV2+ molecules was obtained.