Modulation of vacancy-ordered double perovskite Cs2SnI6 for air-stable thin-film transistors

Vacancy-ordered halide double perovskites are promising non-toxic and stable alternatives for their lead- and tin (II)-based counterparts in electronic and optoelectronic applications. Despite extensive theoretical studies on this emerging family of materials, efforts devoted to the chemical modulation of their thin-film properties and their potential application in electronic devices remain rare. Here, we develop a facile one-step solution processing strategy to tune the film quality of cesium tin (IV) iodide (Cs2SnI6) perovskite and demonstrate its feasibility in thin-film transistor (TFT) application. We reveal critical roles of precursor stoichiometric ratio and solvent engineering in achieving uniform and highly crystalline Cs2SnI6 films with superior electron mobility. We further modulate the electronic properties by incorporating an external manganese (Mn2+) dopant, achieving high-performance air-stable n-channel TFTs and all-perovskite complementary inverters. We anticipate that the present study would pave the way for expanding the environmentally friendly and stable perovskites toward widespread applications.