Ion doping simultaneously increased the carrier density and modified the conduction type of Sb2Se3 thin films towards quasi-homojunction solar cell

Antimony selenide (Sb 2 Se 3 ) has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material. However, the intrinsic low carrier density and electrical conductivity limited its scope of applications. In this work, an effective ion doping strategy was implemented to improve the electrical and photoelectrical performances of Sb 2 Se 3 thin films. The Sn-doped and I-doped Sb 2 Se 3 thin films with controllable chemical composition can be prepared by magnetron sputtering combined with post-selenization treatment based on homemade plasma sintered targets. As a result, the Sn-doped Sb 2 Se 3 thin film exhibited a great increase in carrier density by several orders of magnitude, by contrast, a less increase with one order of magnitude was achieved for the I-doped Sb 2 Se 3 thin film. Additionally, such cation or anion doping could simultaneously modify the conduction type of Sb 2 Se 3 , enabling the first fabrication of a substrate structured Sb 2 Se 3 -based quasi-homojunction thin film solar cell with configuration of Mo/Sb 2 Se 3 -Sn/Sb 2 Se 3 -I/ITO/Ag. The obtained power conversion efficiency exceeding 2% undoubtedly demonstrated its attractive photovoltaic application potential and further investigation necessity.