Electrolyte-Gated Perovskite Transistors Functionalized with Conjugated Polymers

In emerging perovskite transistors, interfacial engineering is pivotal for modulating the effective charge carrier transport; however, the gate dielectric layer and its interface remain unexplored owing to the limited chemical stability of perovskites. Here, we propose an interfacial functionalization with a conjugated polymer to allow the use of a high capacitance electrolyte dielectric in top-gate perovskite transistors. This multifunctional approach, exploiting orthogonal solution-processed polymers, enables blocking of chemical diffusion during the deposition of the dielectric, allows passivation of defects on the perovskite surface, results in air stability enhancement, and boosts mobility via the formation perovskite-polymer hybrid channels. The optimized conjugated polymer-capped lead iodide perovskite transistors showed a remarkable hole mobility of over 30 cm² V^-1 s^-1 at ≤2 V. This result demonstrated the possibility of realizing high mobility through interfacial functionalization of perovskites in transistor applications.