Encapsulated X-Ray Detector Enabled by All-Inorganic Lead-Free Perovskite Film with High Sensitivity and Low Detection Limit

The sensitive detection of low-dose X-ray radiation is essential to many X-ray applications. In this article, the ultrasensitive X-ray detector based on pure Cs2 AgBiBr6 all-inorganic lead-free perovskite film is successfully demonstrated and encapsulated using a metal casing with a Be window. The high-quality Cs2 AgBiBr6 films are obtained through the low-cost solution process with long electron-hole diffusion length (700 nm) and long carrier lifetime (750 ns). Benefiting from the excellent properties of the Cs2 AgBiBr6 film and the stable ambient provided by the packaging module, the resulting device exhibits attractive X-ray detection capabilities with a minimum detectable dose rate of 145.2 {\mathrm {nGy}}_{air}\text{s}^{-1} and a detection sensitivity up to 1.8\times 10^{4}\,\,\mu {\mathrm {CGy}}_{air}{}^{-1} cm -2 , which is about a thousand times higher than the sensitivity achieved with commercial a-Se X-ray detectors. Besides, the encapsulated device maintains superior detection performance after 2 months of storage, indicating the favorable reliability of the encapsulated device. This article demonstrates a possibility to use Cs2 AgBiBr6 perovskite film and Be window for the sensitive X-ray detection, which will inspire further development of radiation electronics by utilizing all-inorganic lead-free perovskite.