Vertical Organic–Inorganic Hybrid Perovskite Schottky Junction Transistors

While organolead halide perovskite materials have attracted considerable attention for high efficiency solar cells, they have shown little potential for use in field-effect transistors (FETs) due to the limited current modulation at room temperature. Here, by developing a vertically gated methylammonium lead iodide (MAPbI₃)/indium-tin oxide (ITO) Schottky junction, a room temperature-operable vertical MAPbI₃ thin-film transistor is reported. Due to the injection-controlled gating mechanism as well as the vertical channel structure, a current modulation ratio up to 10⁴ is achieved. Fabrication of a nanoporous ITO source electrode forming a highly rectifying Schottky junction with the MAPbI₃ layer is the key for the large current modulation. It is discovered that the electron transporting layers on top of the MAPbI₃ layer play an important role in achieving a large current rectification of 10⁷ at the Schottky junction and hence large current on/off ratios of the resulting transistor.