Electrically active defects in polycrystalline and single crystal metal halide perovskite

We studied electrically active defects in CsPbBr3 polycrystalline films and single crystals samples using the thermally stimulated currents (TSC) technique in the temperature range 100-400 K. Below room temperature, both polycrystalline and single-crystals TSC emission is composed by a quasi-continuum of energy levels in the range 0.1-0.3 eV, and capture cross sections ∼10-21 cm2. Above room temperature, TSC analysis reveals the presence of defect states in the range 0.40-0.52 eV only in polycrystalline samples, whereas these intermediate energy states are absent in TSC detected in single crystals. In polycrystalline films, the occupancy changes of an energy level at 0.45 eV strongly influences the room temperature photoconductivity, giving rise to slow transients due to defect passivation. In single-crystals, where intermediate energy states are absent, the photoconductivity response during illumination is almost stable and characterized by fast rise/decay times, a promising result for future applications of this material in photodetection and dosimetry.