High-mobility electrolyte-gated perovskite transistors on flexible plastic substrate via interface and composition engineering
Vivian Nketia‐Yawson, Benjamin Nketia‐Yawson, Jea Woong Jo
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 (MAPbI 3 ), formamidinium (FA) lead triiodide (FAPbI 3 ), and mixed A-cation lead triiodide (FA 0.2 MA 0.8 PbI 3 )), the P3HT-capped FAPbI 3 FETs exhibited the best hole mobility of 24.55 cm 2 V −1 s −1 (average ≈ 16.83 ± 4.86 cm 2 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 FAPbI 3 perovskite. These findings demonstrate the potential of the proposed approach for achieving high mobility and low-voltage operated flexible perovskite-based transistor devices.