Solution-Processed Perovskite Gate Insulator for Sub-2 V Electrolyte-Gated Transistors

초록

By virtue of their semiconducting and electrolytic characteristics, hybrid organic-inorganic perovskites have received intense research attention in various applications, which include energy, electronics, and display technologies. While research studies on the semiconducting or electronic properties of perovskite materials in solar cells and light-emitting diodes have been actively investigated, studies on their electrolytic or ionic behavior have rarely been conducted. To probe the electrolyte properties of the metal halide perovskite, we have fabricated solution-processed zinc oxide (ZnO) thin-film transistors using a methylammonium lead iodide (CH3NH3PbI3) perovskite thin film as a gate insulator material. The resulting perovskite film revealed ionic characteristics, with an ionic conductivity of about 10(-8) S/cm. The perovskite-gated ZnO transistors exhibited typical n-type characteristics with an average field-effect mobility of 0.047 cm(2)/V s at a low applied voltage below 2 V because of the electrical double layer formed by mobile I- anions and CH3NH3+ cations in the perovskite gate dielectric. In addition, the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) transistors gated with the perovskite showed an abnormal increase in the channel current when applying positive gate bias, probably because of the confined ion movement inside the perovskite gate insulator.

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