Wearable electronics need flexible components. Flexible X-ray detectors could be useful in, e.g., industrial, security, and medical applications. This requires flexible materials that are photoresponsive under X-ray irradiation.
Molecular perovskites might be useful semiconductor materials for such applications. The ammonium ion in metal-free molecular perovskites of the type A(NH4)X3 (A = organic molecule, X = halide) can be replaced by a monovalent metal to obtain new AM(I)X3-type perovskites. These materials maintain some of the useful properties of metal-free molecular perovskites, such as low cost and weight, while the metal can enhance the material’s X-ray attenuation capability.
Kui Zhao, Shaanxi Normal University, Xi’an, China, Shengzhong Frank Liu, Shaanxi Normal University, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and University of the Chinese Academy of Sciences, Beijing, and colleagues have synthesized a new molecular perovskite, DABCO-CsBr3 (DABCO = N,N′-diazabicyclo[2.2.2]octonium), for use in flexible X-ray detectors. The material was prepared from DABCO, CsBr, and HBr in aqueous solution and obtained in the form of colorless crystals.
The team found that DABCO-CsBr3 has good mechanical properties for use in flexible devices. As expected, compared with the metal-free equivalent DABCO-NH4Br3, DABCO-CsBr3 has a stronger X-ray attenuation capability. The researchers built a flexible X-ray detector, using a poly(vinylidene fluoride) (PVDF) polymer matrix that was mixed with DABCO-CsBr3 to create a composite film. This film shows a linear relationship between the X-ray-induced current density and the X-ray dose rate. According to the team, the material could have applications in X-ray security screening systems or medical diagnostics.
- Efficient Eco-Friendly Flexible X-ray Detectors Based on Molecular Perovskite,
Qingyue Cui, Nuo Bu, Xinmei Liu, Haojin Li, Zhuo Xu, Xin Song, Kui Zhao, Shengzhong Frank Liu,
Nano Lett. 2022.