Field-effect transistors with vacuum-deposited organic-inorganic perovskite films as semiconductor channels

摘要

Films of the organic-inorganic layered perovskite (C_6H_5C_2H_4NH_3)_2SnI_4 were vacuum-deposited on substrates heated at various temperatures (T_(sub)) to investigate the influence of T_(sub) on their film quality and transistor performance (hole mobilities, threshold voltages, and current on/off ratios). Appropriate substrate heating at T_(sub) = 60℃ during vacuum deposition led to better-developed perovskite films with larger grains. These films exhibited the best transistor performance in comparison with films fabricated at the other T_(sub). The transistor performance was further enhanced by reducing perovskite semiconductor thickness (t) because of a reduction of bulk resistance in a top-contact/bottom-gate transistor structure. By utilizing the optimized T_(sub) of 60 ℃ and t of 31 nm, we obtained the most improved hole mobility of 0.78 ± 0.24 cm~2/V s, about 5000 times the hole mobilities of our initial transistors fabricated at T_(sub) = 24 ℃ and t = 50 nm.