Functional impact of gate dielectrics in emerging metal halide perovskite field-effect transistors

Metal halide perovskites (MHPs) have gained enormous research interest in the field of photovoltaics and optoelectronic devices owing to their excellent structural and electronic properties, which make them highly suitable field-effect transistors (FETs). With the recent rapid advancement in MHP FET applications, studies have achieved record charge carrier mobilities by exploring various engineering approaches and gate dielectrics. However, the limited understanding of the mechanism and stability of perovskite FETs severely hinders its real-world commercialization. In this review, we discuss the essential role and effect of gate dielectrics on the charge transport of MHP FETs. To this end, first, the fundamentals of MHPs, field-effect transistors, and the role of the gate dielectric are introduced briefly, after which the recent performance of perovskite transistors gated by various oxide, polymeric, and electrolyte gate dielectrics are discussed. Next, we review the effect of MHP channel morphology and microstructures, ion migration, and ambient conditions on the stability of emerging perovskite transistors. In addition, strategic approaches for achieving hysteresis-free perovskite transistors, including compositional engineering, passivation, and doping, are described. Lastly, up-and-coming flexible FETs based on MHPs and a general insight into synergistic effects between gate dielectrics and MHP electronic and charge-transporting properties are discussed.