765
Views
31
Crossref
32
WoS
31
Scopus
3
CSCD
Spatial resolution is an important criterion to evaluate the performance of a scintillation screen for X-ray imaging. Perovskite-based X-ray screen, usually made of powders or polycrystalline films, suffers from low spatial resolution (~ 200 μm) due to the large thickness of scintillation layer despite of their compelling sensitivity to X-ray dose. In this work, a concentrated colloid of CsPbBr3 nanosheets was synthesized via a co-precipitation method at ambient condition. By drop casting, smooth scintillation screens of varied thickness were formed through self-assembly, which exhibited both high internal and external photoluminescence quantum yield (PL QY) (84.5% and 75.1%, respectively). The screen-based X-ray detector showed a high sensitivity down to 27 nGy/s, two orders of magnitude lower than the regular dose for medical diagnostics. Importantly, the screen of optimal thickness of 15 μm showcased an unprecedented spatial resolution (26 μm) when used for X-ray radiography, representing one order of magnitude improvement in perovskite community.
This work is supported by the National Natural Science Foundation of China (No. 21805111), Natural Science Foundation of Shandong Province (No. ZR2020YQ12), and Taishan Scholar Project of Shandong Province (No. tsqn201812082).