Synthesis of Inorganic Metal Halide Perovskite for Radiation Detectors

Research to develop high-efficiency ambient temperature radiation detectors are ongoing due to the demand on measuring x-rays and gamma rays with high energy resolution and sensitivity. Materials such as CZT have complicated crystal growth conditions such as precipitates in crystals that can degrade detector performance due to electric defects that disturb photogenerated carriers hopping. The inorganic wide-bandgap perovskites such as CsPbBr₃ (CBP) are promising for the crystal design with homogeneous nucleation using Bridgman method. This material has high mobility-lifetime product (10^-2cm²V^-1), low defect densities, and long-term stability for photon and charge particle detection. The synthesis of a CBP perovskite by means of Bridgman method was investigated including phase transformations at specific temperature points. A vertical translation mechanism was employed to transport a vacuum-sealed ampoule to grow CPB crystals. The ingot processing and surface treatment techniques will be discussed. The grown crystals were characterized using photoluminescence (room temperature and cryogenic), optical and scanning electron microscopy. We will also provide data on the compositional uniformity via XRD, EDS and SIMS techniques. Electrical characterization of the samples was performed for IV analysis.