Facile Strategy for Facet Competition Management to Improve the Performance of Perovskite Single-Crystal X-ray Detectors
Jinmei Song, Xiaopeng Feng, Huayang Li, Weijun Li, Tong Lu, Chunjie Guo, Huimao Zhang, Haotong Wei, Yang Bai
Abstract
Methylammonium lead tribromide perovskite single crystals have been demonstrated to be good candidates as sensitive X-ray detectors in direct detection mode in recent years. However, its X-ray detection performance based on the orientation of different facets is still not clear. Here, we developed a facile strategy to chemically expose the [110] facet of single crystals from low-cost solution processes by tailoring the nonstoichiometry of feeding ions to selectively suppress the growth of the [100] facet. In contrast to physically cutting and sawing single-crystal ingots, this avoids damage to the fragile single crystals as well as orientation errors, more suitable for the naturally soft lattice. Compared to the [100] facet, the exposed [110] facet of perovskite single crystals exhibits a smaller trap density and excellent charge carrier transportation properties, leading to an improved sensitivity of 3928.3 μC/Gyair/cm2 to 120 keV hard X-rays, which potentially outperforms the currently dominating CsI scintillator of a commercial digital radiography (DR) medical imager for a routine health check.