Growth and Performance of Perovskite Semiconductor CsPbX (X = Cl, Br, I, or Mixed Halide) for Detection and Imaging Applications.

The material family halide perovskites has been critical in recent room-temperature radiation detection semiconductor research. Cesium lead bromide (CsPbBr) is a halide perovskite that exhibits characteristics of a semiconductor that would be suitable for applications in various fields. In this paper, we report on the correlations between material purification and crystal material properties. Crystal boules of CsPbX (where X = Cl, Br, I, or mixed) were grown with the Bridgman growth method. We describe in great detail the fabrication techniques used to prepare sample surfaces for contact deposition and sample testing. Current-voltage measurements, UV-Vis and photocurrent spectroscopy, as well as photoluminescence measurements, were carried out for material characterization. Bulk resistivity values of up to 3.0 × 10 Ω∙cm and surface resistivity values of 1.3 × 10 Ω/□ indicate that the material can be used for low-noise semiconductor detector applications. Preliminary radiation detectors were fabricated, and using photocurrent measurements we have estimated a value of the mobility-lifetime product for holes (μτ) of 2.8 × 10 cm/V. The results from the sample testing can shed light on ways to improve the crystal properties for future work, not only for CsPbX but also other halide perovskites.