High-Performance Layered Perovskite Transistors and Phototransistors by Binary Solvent Engineering

Abstract

Perovskite materials have displayed remarkable performance when used in photovoltaic devices. In comparison, research on their application in thin-film transistors (TFTs) has been developing slowly. We report reliable high-performance p-channel lead-free layered perovskite phenethylammonium tin iodide TFTs using simple and easily repeatable one-step spin-coating with premixed binary solvents of N,N-dimethylformamide (DMF) and chlorobenzene (CB)/ethyl acetate (EA). CB/EA antisolvent addition facilitates nucleation and formation of films with oriented grain ripening and full coverage. The champion perovskite TFT shows a fivefold increase in the mobility (3.8 cm2 V–1 s–1) and a twofold magnitude increase in the current on/off ratio (∼106) with improved bias stress stability. Using well-developed n-channel indium gallium zinc oxide TFTs, a complementary inverter with a high gain of ∼30 is demonstrated. Moreover, with efficient charge transport, transistor amplification function, and pronounced photogating properties, the optimized perovskite phototransistors show a remarkably high photodetectivity of up to 3.2 × 1017 Jones. This simple and highly repeatable method has attracted more attention for fabricating printed high-performance perovskite TFTs and phototransistors beyond energy sector applications.