Growth and Characterization of Radiation Sensors Based on Single Crystals of Hybrid Metal–Organic Methylammonium Lead Bromide and Iodide Perovskite

Abstract

The inverse temperature (T)-dependent methods yield single crystals of methylammonium lead halide perovskite with strained lattices. In contrast, the antisolvent diffusion method (antisolvent-vapor crystallization (AVC)) produces unstrained MAPbBr3 crystals with more uniform growth features and lower density of defects. The powder X-ray diffraction (XRD) measurements confirm the cubic and the tetragonal structure of the MAPbBr3 and the MAPbI3 samples, respectively. The XRD pole figure measurements (MAPbBr3) reveal a roughly parallel dominant (100) lattice plane to the sample surface. An optimal crystal growth combines growth of a seed on an oriented substrate by the AVC method followed by either the AVC or a T-dependent method. The estimated resistivity ρ and the density of trap state ntrap values for the MAPbI3 samples are 107 Ωcm and 1010 cm−3, respectively. The X-ray detection test reveals promising electrical properties of the MAPbI3 material. Results from the Hall measurements in van der Pauw geometry for the MAPbBr3 samples agree with those in the literature: the charge-carrier concentration of 109−1010 cm−3 and the mobility of 7–289 cm2 V−1s−1, ntrap of 109−1010 cm−3, and ρ of 107–108 Ωcm. These electrical parameters indicate that the MAPbBr3 samples satisfy requirements for radiation sensors.