X-ray detectors are widely used in imaging, security-screening, non-destructive inspection, industrial products and scientific research.
Organic-inorganic lead halide perovskites with low cost and facile preparation process have shown excellent properties in direct X-ray detection. However, the ion migration in perovskite materials accelerates its decomposition, deteriorating device performance, and causing baseline drift and lower imaging resolution.
Recently, a research team led by Prof. LIU Shengzhong from the Dalian Institute of Chemical Physics(DICP) of the Chinese Academy of Sciences, in collaboration with Dr. LIU Yucheng Liu, Dr. XU Zhuo and Dr. YANG Zhou from Shaanxi Normal University, developed 0D-structured lead-free perovskite single crystals for highly sensitive stable X-ray imaging.
They developed an effective strategy to grow superior inch-sized high-quality 0D-structured lead-free (CH3NH3)3Bi2I9 perovskite-like single crystals (MA3Bi2I9 PSCs).
Compared with other perovskite materials, these samples showed significantly lower ion migration, reduced dark current and better environmental stability, which could be used to design and fabricate a new type of 0D-structured lead-free X-ray detector.
The X-ray detectors show high sensitivity and a very low detection limit, a factor of 66 below that required for regular medical diagnostics.
The study showed that, compared with 2D and 3D perovskites, the present 0D structure effectively prevents ion migration, showing the best long-term stability among all perovskites reported.
The combination of large crystal size and excellent X-ray response inspire researchers to design and fabricate the first 0D-structured lead-free MA3Bi2I9 single-crystal X-ray imaging system with reduced X-ray dose and improved resolution.
Their findings were published in Matter. (Text by DUAN Lianjie and LIU Yucheng)
Top: Photographs of typical MA3Bi2I9 SCs and the X-ray sensitivity of the MA3Bi2I9 SC X-ray detector as a function of applied electric field; Below: Photograph and corresponding X-ray images of a metallic key with partially wrapped in rubber and a naked metal key. (Image by DUAN Lianjie and LIU Yucheng)