Viable and Area Scalable Selenization Process for Deposition of [001]‐Oriented Sb ₂ Se ₃ Thin Films and Fabrication of Substrate Configured Sb ₂ Se ₃ /CdS Heterojunction Solar Cells

Antimony chalcogenide (Sb 2 Se 3 ) has emerged as a highly promising absorber material for thin‐film photovoltaics due to its favorable bandgap, strong optical absorption in the visible region, simple binary composition, and the environmentally friendly nature of its constituents. The photovoltaic performance of Sb 2 Se 3 is greatly influenced by its orientation with reference to the substrate due to its anisotropic nature. Achieving a vertical growth orientation of Sb 2 Se 3 ribbons perpendicular to the substrate is considered a key step to improve photoexcited carrier transport and, consequently, to develop high‐efficiency solar cells. This necessitates a need to devise a strategic approach to attain the preferred orientation along [001] direction. Herein, the fabrication details of substrate‐configured Sb 2 Se 3 solar cells and their performance analysis are presented. Sb 2 Se 3 absorber with a predominant [001] orientation is achieved through the selenization of antimony precursor films. A promising power conversion efficiency of 4.6%, with an open‐circuit voltage of 348 mV, short‐circuit current denisty of 31.6 mA cm −2 , and fill factor FF of 41%, has been achieved for the best‐performing device with an active area of 0.33 cm 2 . Assessment of capacitance–voltage profiling, quantum efficiency measurements, and dark current–voltage analysis helps elucidate the key factors that influence the device performance.