Moser Annina, Yarema Olesya, Garcia Gregorio, Luisier Mathieu, Longo Filippo, Billeter Emanuel, Borgschulte Andreas, Yarema Maksym, Wood Vanessa
Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zurich, Gloriastrasse 35, CH-8092 Zurich, Switzerland.
Departamento de Tecnología Fotónica y Bioingeniería & Instituto de Energía Solar, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria, ES-20840 Madrid, Spain.
Chem Mater. 2023 Aug 9;35(16):6323-6331. doi: 10.1021/acs.chemmater.3c00911. eCollection 2023 Aug 22.
Aliovalent I-V-VI semiconductor nanocrystals are promising candidates for thermoelectric and optoelectronic applications. Famatinite CuSbSe stands out due to its high absorption coefficient and narrow band gap in the mid-infrared spectral range. This paper combines experiment and theory to investigate the synthesis and electronic structure of colloidal CuSbSe nanocrystals. We achieve predictive composition control of size-uniform CuSbSe ( = 1.9-3.4) nanocrystals. Density functional theory (DFT)-parametrized tight-binding simulations on nanocrystals show that the more the Cu-vacancies, the wider the band gap of CuSbSe nanocrystals, a trend which we also confirm experimentally via FTIR spectroscopy. We show that Sb antisite defects can create mid-gap states, which may give rise to sub-bandgap absorption. This work provides a detailed study of CuSbSe nanocrystals and highlights the potential opportunities as well as challenges for their application in infrared devices.
异价I-V-VI族半导体纳米晶体是热电和光电应用的有前途的候选材料。辉锑铜矿CuSbSe因其在中红外光谱范围内的高吸收系数和窄带隙而脱颖而出。本文结合实验和理论来研究胶体CuSbSe纳米晶体的合成和电子结构。我们实现了尺寸均匀的CuSbSe（= 1.9 - 3.4）纳米晶体的预测性组成控制。对纳米晶体进行的密度泛函理论（DFT）参数化紧束缚模拟表明，Cu空位越多，CuSbSe纳米晶体的带隙越宽，我们也通过傅里叶变换红外光谱（FTIR）在实验中证实了这一趋势。我们表明，Sb反位缺陷会产生带隙中间态，这可能导致亚带隙吸收。这项工作对CuSbSe纳米晶体进行了详细研究，并突出了其在红外器件应用中的潜在机遇和挑战。
