All‐Vacuum‐Processed Sb2(S,Se)3 Thin Film Photovoltaic Devices via Controllable Tuning Seed Orientation

Abstract

AbstractQuasi‐one‐dimensional antimony sulfoselenide (Sb2(S,Se)3) semiconductor is one of the most promising light‐harvesting materials owing to its simple phase and tunable absorption spectra. However, the oriented [Sb4(S,Se)6]n ribbons of Sb2(S,Se)3 thin films nearly horizontally stacked in parallel to the substrate severely hinders the transport of carriers, yet is critical to control the absorber orientation growth for high‐performance Sb2(S,Se)3 solar cells. Herein, a new close spaced sublimated (CSS) CdS buffer layer with high crystallization is introduced for the development of all‐vacuum‐processed Sb2(S,Se)3 solar cells that attempt to induce the orientation of Sb2(S,Se)3 absorbers to achieve effective carrier transport and reduce the adverse effects. The resulting Sb2(S,Se)3 solar cells with CSS‐CdS buffer layers exhibit a prominent [221] orientation and better heterointerfaces as well as lower defect densities and longer capture lifetime compared to the commonly solar cells used chemically deposited CdS buffer layers, as a result of suppressed the non‐radiative recombination. The optimized solar cells, yield up to an efficiency of 7.12%, is the first for an all‐vacuum‐process for Sb2(S,Se)3 solar cells.