Solution-processed vanadium oxides as a hole-transport layer for Sb2Se3 thin-film solar cells

Antimony selenide (Sb2Se3) is a promising light absorber material for solar cells because of its superior photovoltaic properties. However, the current performance of the Sb2Se3 solar cell is much lower than its theoretical value (similar to 32%) due to its low open-circuit voltage (V-OC). In this paper, we have demonstrated inorganic vanadium oxides (VOx) as a hole transport layer (HTL) for Sb2Se3 solar cells to enhance efficiency through the V-OC improvement. Here, a solution-processed VOx through the decomposition of the triisopropoxyvanadium (V) oxide is deposited on the Sb2Se3 absorber layer prepared by close-spaced sublimation (CSS). With VOx HTL, the built-in voltage (V-bi) is significantly increased, leading to improved V-OC for the Sb2Se3 solar cell devices. As a result, the efficiency of the device increases from an average efficiency of 5.5% to 6.3% with the VOx.