High-mobility electrolyte-gated perovskite transistors on flexible plastic substrate via interface and composition engineering

Abstract

Perovskite has emerged as a promising semiconductor for flexible electronics. However, perovskite-based flexible field-effect transistors (FETs) have typically exhibited a low performance owing to their use of conventional polymer dielectrics. To address this, interfacial and compositional engineering has been employed in emerging perovskite transistors to boost their charge-carrier transport. Here, we introduce the interfacial engineering of a perovskite surface using solution-processed poly(3-hexylthiophene) (P3HT) to enable the use of an electrolyte dielectric. Among the fabricated lead iodide-based perovskite devices (methylammonium (MA) lead triiodide (MAPbI3), formamidinium (FA) lead triiodide (FAPbI3), and mixed A-cation lead triiodide (FA0.2MA0.8PbI3)), the P3HT-capped FAPbI3 FETs exhibited the best hole mobility of 24.55 cm2 V-1 s-1 (average approximate to 16.83 +/- 4.86 cm2 V-1 s-1) on a plastic substrate at sub-2 V. This notable performance was attributed to an increase in the charge carrier density in the perovskite-P3HT hybrid channel owing to the high capacitance of the electrolyte dielectric and better injection properties of the FAPbI3 perovskite. These findings demonstrate the potential of the pro-posed approach for achieving high mobility and low-voltage operated flexible perovskite-based transistor devices.