α-Particle Detection and Charge Transport Characteristics in the A3M2I9 Defect Perovskites (A = Cs, Rb; M = Bi, Sb)

作者：Kyle M. McCall, Zhifu Liu, Giancarlo Trimarchi, Constantinos C. Stoumpos, Wenwen Lin, Yihui He, Ido Hadar, Mercouri G. Kanatzidis, Bruce W. Wessels · 发表于：ACS Photonics · 年份：2018 · DOI：10.1021/acsphotonics.8b00813 · 被引用次数：135 · 研究领域：Perovskite Materials and Applications、Optical properties and cooling technologies in crystalline materials、Solid-state spectroscopy and crystallography

We have investigated the defect perovskites A 3 M 2 I 9 (A = Cs, Rb; M = Bi, Sb) as materials for radiation detection. The phase purity of Bridgman-grown A 3 M 2 I 9 single crystals was confirmed via high-resolution synchrotron X-ray diffraction, while density functional theory calculations (DFT) show surprisingly dispersive bands in the out-of-plane direction for these layered materials, with low effective masses for both holes and electrons. Accordingly, each of the four A 3 M 2 I 9 defect perovskites showed response to 241 Am α-particle irradiation for hole and electron electrode configurations, a remarkable ambipolar response that resembles the 3D halide perovskites. The electron response spectra were used to estimate the mobility–lifetime product (μτ) e for electrons in these materials, with Rb 3 Bi 2 I 9 showing the lowest (μτ) e value of 1.7 × 10 –6 cm 2 V –1 and Cs 3 Bi 2 I 9 the highest (μτ) e of 5.4 × 10 –5 cm 2 V –1 . The rise time of the α-particle-generated pulse was used to estimate the electron mobility μ e of the A 3 M 2 I 9 defect perovskites, which ranged from 0.32 cm 2 V –1 s –1 for Rb 3 Sb 2 I 9 to 4.3 cm 2 V –1 s –1 in Cs 3 Bi 2 I 9 . Similar analysis of the hole response spectra yielded (μτ) h values for each A 3 M 2 I 9 compound, with Cs 3 Bi 2 I 9 again showing the highest (μτ) h value of 1.8 × 10 –5 cm 2 V –1, while Rb 3 Bi 2 I 9 showed the lowest (μτ) h with 2.0 × 10 –6 cm 2 V –1 . Rise time analysis gave hole mobilities ranging from 1.7 cm 2 V –1 s ...