Thickness‐dependent carriers transport in Sb ₂ Se ₃ thin film solar cells

Abstract The structural design of n‐i‐p in antimony selenide (Sb 2 Se 3 ) thin film solar cells can effectively improve the low carrier collection efficiency caused by the lower doping concentration of Sb 2 Se 3 . However, the unideal carrier transport ability of the intrinsic light‐absorbing layer remains a major limitation for its power conversion efficiency improvement. Herein, it is discovered that the carrier transport in Sb 2 Se 3 thin films strongly depends on the film thickness of the absorber layer in n‐i‐p structure. By exploring the carrier transport mechanism under different thicknesses of light‐absorbing layers, a suitable absorber layer with thickness of 550 nm is demonstrated can effectively separate, transport, and extract photogenerated carriers in Sb 2 Se 3 solar cells. Finally, the vapor transport deposition processed Sb 2 Se 3 solar cells achieve the highest PCE of 7.62% with a short‐circuit current density of 30.71 mA·cm −2 . This finding provides a constructive guidance for the future researches on Sb 2 Se 3 thin film solar cells with n‐i‐p structure.