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

Quasi-one-dimensional antimony sulfoselenide (Sb-2(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 [Sb-4(S,Se)(6)](n) ribbons of Sb-2(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 Sb-2(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 Sb-2(S,Se)(3) solar cells that attempt to induce the orientation of Sb-2(S,Se)(3) absorbers to achieve effective carrier transport and reduce the adverse effects. The resulting Sb-2(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 Sb-2(S,Se)(3) solar cells.