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 ≈ 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 proposed approach for achieving high mobility and low-voltage operated flexible perovskite-based transistor devices.