Surface Engineering of Methylammonium Lead Bromide Perovskite Crystals for Enhanced X-ray Detection
Abraha Tadese Gidey, Yuki Haruta, Artur P. Herman, M. Grodzicki, Anna M. Melnychenko, Dominika Majchrzak, Somnath Mahato, Ernest Rogowicz, M. Syperek, R. Kudrawiec, Makhsud I. Saidaminov, Ahmed L. Abdelhady
Abstract
High Resolution Image Download MS PowerPoint Slide The surface quality of lead halide perovskite crystals can extremely influence their optoelectronic properties and device performance. Here, we report a surface engineering crystallization technique in which we in situ grow a polycrystalline methylammonium lead tribromide (MAPbBr 3 ) film on top of bulk mm-sized single crystals. Such MAPbBr 3 crystals with a MAPbBr 3 passivating film display intense green emission under UV light. X-ray photoelectron spectroscopy demonstrates that these crystals with emissive surfaces are compositionally different from typical MAPbBr 3 crystals that show no emission under UV light. Time-resolved photoluminescence and electrical measurements indicate that the MAPbBr 3 film/MAPbBr 3 crystals possess less surface defects compared to the bare MAPbBr 3 crystals. Therefore, X-ray detectors fabricated using the surface-engineered MAPbBr 3 crystals provide an almost 5 times improved sensitivity to X-rays and a more stable baseline drift with respect to the typical MAPbBr 3 crystals.