Temperature Dependence of Charge Transport Properties of Quasi-2D Chiral Perovskite Thin-Film Field-Effect Transistors

Chiral halide perovskite materials promise both superior light response and the capability to distinguish circularly polarized emissions, which are especially common in the fluorescence spectra of organic chiral materials. Herein, thin-film field-effect transistors (FETs) based on chiral quasi-two-dimensional perovskites are explored, and the temperature dependence of the charge carrier transport mechanism over the broad temperature range (80-300 K) is revealed. A typical p-type charge transport behavior is observed for both left-handed (S-C₆H₅(CN₂)₂NH₃)₂(CH₃NH₃)_n−1Pb_nI_3n+1 and right-handed (R-C₆H₅(CN₂)₂NH₃)₂(CH₃NH₃)_n−1Pb_nI_3n+1 chiral perovskites, with maximum carrier mobilities of 1.7 × 10^-5 cm² V^-1 s^-1 and 2.5 × 10^-5 cm² V^-1 s^-1 at around 280 K, respectively. The shallow traps with smaller activation energy (0.03 eV) hinder the carrier transport over the lower temperature regime (80-180 K), while deep traps with 1 order of magnitude larger activation energy than the shallow traps moderate the charge carrier transport in the temperature range of 180-300 K. From the charge carrier mechanism point of view, impurity scattering is established as the dominant factor from 80 K until around 280 K, while phonon scattering becomes predominant up to room temperature. Responsivities of 0.15 A W^-1 and 0.14 A W^-1 for left-handed and right-handed chiral perovskite FET devices are obtained. © 2024 American Chemical Society.