Thermochromism and X-ray Detection Capabilities of a Hybrid Double Metal Halide Perovskite (C3H12N2)2AgBiBr8

Abstract

Two-dimensional (2D) layered hybrid double metal halide perovskites have recently gained significant attention as lead-free and environmentally benign alternatives to lead halide perovskites. In this study, we report the photophysical properties of a 2D Dion-Jacobson (DJ) type hybrid double perovskite (C 3 H 12 N 2 ) 2 AgBiBr 8 , which exhibits both reversible thermochromism and promising X-ray radiation detection capabilities. This material shows transition from a lowtemperature monoclinic P2 1 /n phase to a high-temperature monoclinic C2/m phase at 121.83℃ along with a color change from yellow to bright orange. The phase transition is reversible and both single crystals and bulk powder samples of (C 3 H 12 N 2 ) 2 AgBiBr 8 remain stable for more than 30 heating-cooling cycles. Optical property characterizations show that (C 3 H 12 N 2 ) 2 AgBiBr 8 is a semiconductor with an indirect band gap of 2.42 eV. The material demonstrates a semiconductor resistivity of 2.8×10 10 Ω•cm, lower than the other reported DJ-type hybrid double perovskites and also shows response towards soft X-rays (8 keV) with a detector sensitivity of 188.52 μCGy -1 cm - 2 . These properties along with a very high signal-to-noise ratio (SNR) value (111.45) indicate the potential of (C 3 H 12 N 2 ) 2 AgBiBr 8 for direct radiation detection.