Kilogram-Scale Crystallogenesis of Halide Perovskites for Gamma-Rays Dose Rate Measurements.

Gamma-rays ( γ -rays), wherever present, e.g., in medicine, nuclear environment, or homeland security, due to their strong impact on biological matter, should be closely monitored. There is a need for simple, sensitive γ -ray detectors at affordable prices. Here, it is shown that γ -ray detectors based on crystals of methylammonium lead tribromide (MAPbBr ₃ ) ideally meet these requirements. Specifically, the γ -rays incident on a MAPbBr ₃ crystal generates photocarriers with a high mobility-lifetime product, allowing radiation detection by photocurrent measurements at room temperatures. Moreover, the MAPbBr ₃ crystal-based detectors, equipped with improved carbon electrodes, can operate at low bias (≈1.0 V), hence being suitable for applications in energy-sparse environments, including space. The γ -ray detectors reported herein are exposed to radiation from a  ⁶⁰ Co source at dose rates up to 2.3 Gy h ^-1  under ambient conditions for over 100 h, without any sign of degradation. The excellent radiation tolerance stems from the intrinsic structural plasticity of the organic-inorganic halide perovskites, which can be attributed to a defect-healing process by fast ion migration at the nanoscale level. The sensitivity of the γ -ray detection upon volume is tested for MAPbBr ₃  crystals reaching up to 1000 cm ³ (3.3 kg in weight) grown by a unique crystal growth technique.
Competing Interests: The authors declare no conflict of interest.
(© 2020 The Authors. Advanced Science published by Wiley‐VCH GmbH.)