Highly efficient and stable planar heterojunction solar cell based on sputtered and post-selenized Sb₂Se₃ thin film

Antimony selenide (Sb₂Se₃) is regarded as one of the key alternative absorber materials for conventional thin film solar cells due to its excellent optical and electrical properties. Here, we proposed a Sb₂Se₃ thin film solar cell fabricated using a two-step process magnetron sputtering followed by a post-selenization treatment, which enabled us to optimize the best quality of both the Sb₂Se₃ thin film and the Sb₂Se₃/CdS heterojunction interface. By tuning the selenization parameters, a Sb₂Se₃ thin film solar cell with high efficiency of 6.06% was achieved, the highest reported power conversion efficiency of sputtered Sb₂Se₃ planar heterojunction solar cells. Moreover, our device presented an outstanding open circuit voltage (VOC) of 494 mV which is superior to those reported Sb₂Se₃ solar cells. State and density of defects showed that proper selenization temperature could effectively passivate deep defects for the films and thus improve the device performance.