Solution-processed MAPbBr${}_3$ and CsPbBr${}_3$ single-crystal detectors with improved X-ray sensitivity via interfacial engineering

Organic-inorganic hybrid perovskites have been recognized as prospective materials for use in radiation detection application due to their high atomic number, ease of crystal processing, and excellent electronic properties. Herein, solution-synthesized MAPbBr${}_3$ and CsPbBr${}_3$ detectors with different structures are constructed. Charge diffusion length and trap density analysis reveal that CsPbBr${}_3$ possesses better thermal stability but worse charge-transport properties than MAPbBr${}_3$. To improve the signal current under X-ray radiation, MoO${}_3$ is applied as a hole-extraction layer to increase hole-carrier collection. The sensitivity of X-ray detectors with MoO${}_3$ layer can reach up to 2552 μC Gy${}_{air}$${}^{-1}$ cm${}^{-2}$ at an electric field of 45 V cm${}^{-1}$, which is higher than that without the MoO${}_3$ layer. It is shown that charge-transport capability significantly affects the response of the signal current to X-ray radiation; it also reveals the importance of interface engineering as a means to realize high-sensitivity X-ray detectors. (© 2020 WILEY‐VCH Verlag GmbH and Co. KGaA, Weinheim)