Highly Efficient Inch‐Sized Cs₃Cu₂I₅: In Single Crystal for Radiation Dose Monitor and Nuclear Battery Applications

Scintillating crystals play a critical role in nuclear energy and radiation detection applications, such as nuclear batteries and radiation dose detectors. Both applications urgently require scintillation crystals with high radioluminescence efficiency. In this work, the Bridgman‐grown 1‐inch Cs 3 Cu 2 I 5 : In single crystals demonstrate the capability of realizing a high‐output‐power nuclear battery and ultrabroad dynamic range radiation dose monitoring. The 1‐inch Cs 3 Cu 2 I 5 : In single crystal has a high photoluminescence quantum yield of 92%, and a high light yield of 32 000 photons MeV −1 under gamma‐ray irradiation. The inch‐sized Cs 3 Cu 2 I 5 : In‐based nuclear battery can achieve a high output power of 1.45 µW, superior to that of most radioluminescent‐type nuclear batteries based on commercial and emerging scintillators. The Cs 3 Cu 2 I 5 : In‐based dosimeter can realize an exceptional dynamic response range of 7.2–46 300 mGy h −1 with a linear correlation coefficient R 2 of 0.9999. This work proves the effectiveness of bulk Cs 3 Cu 2 I 5 : In single crystals, acting as the key component of scintillators toward nuclear battery and radiation dose monitor.