Two-Dimensional Dion–Jacobson Perovskite (NH<sub>3</sub>C<sub>4</sub>H<sub>8</sub>NH<sub>3</sub>)CsPb<sub>2</sub>Br<sub>7</sub> with High X-ray Sensitivity and Peak Discrimination of α-Particles
Bao Xiao, Qihao Sun, Shiyao Wang, Leilei Ji, Yingrui Li, Shouzhi Xi, Binbin Zhang, Junjie Wang, Wanqi Jie, Yadong Xu
Abstract
Two-dimensional (2D) halide perovskites have attracted extensive interest because of their excellent optoelectronic properties, structural diversity, and promising stability. Herein, we grow a novel 2D Dion–Jacobson halide perovskite, (BDA)CsPb2Br7 (BDA = 1,4-butanediamine, NH3C4H8NH32+), which exhibits a large bandgap (∼2.76 eV), high resistivity (∼4.35 × 1010 Ω·cm), and considerable switching ratio (>700), indicating great potential for radiation detection. Both experimental and calculated results demonstrate that (BDA)CsPb2Br7 has a significantly improved mobility compared to those of Ruddlesden–Popper perovskites (BA)2CsPb2Br7 and (i-BA)2CsPb2Br7, which is attributed to the shorter interlayer distance leading to the enhanced orbital interactions. The resulting (BDA)CsPb2Br7 detector along the out-of-plane direction achieves a high X-ray sensitivity of 725.5 μC·Gy–1·cm–2. Another fascinating attribute is that the detector exhibits good peak discrimination with an energy resolution of ∼37% when illuminated by the [email protected] MeV α-particles under a negative bias of 260 V. These results provide a broad prospect for 2D Dion–Jacobson perovskites for future radiation detection applications.