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 Cs
₂
AgBiBr
₆
all-inorganic lead-free perovskite film is successfully demonstrated and encapsulated using a metal casing with a Be window. The high-quality Cs
₂
AgBiBr
₆
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 Cs
₂
AgBiBr
₆
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 nGyairs
^-1
and a detection sensitivity up to 1.8 × 10
⁴
μCGyair
^-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 Cs
₂
AgBiBr
₆
perovskite film and Be window for the sensitive X-ray detection, which will inspire further development of radiation electronics by utilizing all-inorganic leadfree perovskite.