Ultrahigh-Mobility and Solution-Processed Inorganic P-Channel Thin-Film Transistors Based on a Transition-Metal Halide Semiconductor

초록

The development of p-channel devices with comparable electrical performances to their n-channel counterparts has been delayed due to the lack of p-type semiconductor materials and device optimization. In this present work, we successfully demonstrated p-channel inorganic thin-film transistors (TFTs) with high hole mobilities similar to the values of n-channel devices. To boost the device performance, the solution-processed copper iodide (Cul) semiconductor was gated by a solid polymer electrolyte. The electrolyte gating could realize electrical double layer (EDL) formation and a three-dimensional carrier transport channel and thus substantially increased charge accumulation in the channel region and realized a high mobility above 90 cm(2)/(V s) (45.12 +/- 22.19 cm(2)/(V s) on average). In addition, due to the high-capacitance EDL formed by electrolyte gating, the CuI TFTs exhibited a low operation voltage below 0.5 V (Vth = -0.045 V) and a high ON current level of 0.7 mA with an ON/OFF ratio of 1.52 x 10(3). We also evaluated the operational stabilities of CuI TFTs and the devices showed 80% retention under electrical/mechanical stress. All the active layers of the transistors were fabricated by solution processes at low temperatures (<100 degrees C), indicating their potential use for flexible, wearable, and high-performance electronic applications.

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