Alteration of the Optoelectronic Properties of CuInS2 Quantum Dots via Colloidal Annealing

Dehm K, Zanetti A, Fett B, Mauritz V, Hamburger RC, Langford D, Guldi DM, Young ER, Mandel K, Crisp R (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Crystal Growth and Design American Chemical Society

DOI: 10.1021/acs.cgd.4c00150

Abstract

Colloidal semiconductor quantum dots (QDs) have tunable optoelectronic properties, thereby making them interesting materials for applications involving light-matter interactions. However, crystallographic and surface defects greatly impair their potential performance in devices. Herein, we present a straightforward approach to improve the quality of copper indium disulfide (CuInS2) QDs by adjusting the parameters of the colloidal synthesis. By the introduction of prolonged heating times after the nanocrystal growth has already gone to completion, defect states are partially removed. This “colloidal annealing” for varying time spans (from 5 up to 90 min) with longer annealing times correlating with a decreased ratio of emission from defect states compared to band edge emission, results in enhanced color purity. At shorter annealing times, the defects removed are mainly structural, indicated by the transition from mixed crystal phases to an almost phase-pure material. At longer annealing times, further improvements are linked to surface defect removal. Findings from transient absorption spectroscopy further confirm this trend by revealing a decrease in the intensity of a photoinduced absorption feature associated with sub-band gap states compared to the band edge bleach signal. These findings highlight the applicability of colloidal annealing as a straightforward strategy for direct material optimization during colloidal synthesis.

Authors with CRIS profile

Katharina Dehm Lehrstuhl für Chemistry of thin film materials Alberto Zanetti Lehrstuhl für Chemistry of thin film materials Bastian Fett Professur für Anorganische Chemie Vincent Mauritz Lehrstuhl für Chemistry of thin film materials Daniel Langford Lehrstuhl für Physikalische Chemie I Dirk Michael Guldi Lehrstuhl für Physikalische Chemie I Karl Mandel Professur für Anorganische Chemie Ryan Crisp Lehrstuhl für Chemistry of thin film materials

Additional Organisation(s)

FAU Profilzentrum Licht.Materie.Quantentechnologien (FAU LMQ)

Related research project(s)

Solar Reduction of CO2 at Nano-Architectured Photoelectrodes Featuring Advanced Photon Management Feb. 1, 2022 - Feb. 1, 2025

Involved external institutions

Lehigh University US United States (USA) (US)

How to cite

APA:

Dehm, K., Zanetti, A., Fett, B., Mauritz, V., Hamburger, R.C., Langford, D.,... Crisp, R. (2024). Alteration of the Optoelectronic Properties of CuInS2 Quantum Dots via Colloidal Annealing. Crystal Growth and Design. https://doi.org/10.1021/acs.cgd.4c00150

MLA:

Dehm, Katharina, et al. "Alteration of the Optoelectronic Properties of CuInS2 Quantum Dots via Colloidal Annealing." Crystal Growth and Design (2024).

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