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A‐site Cation Engineering for Highly Efficient MAPbI 3 Single‐Crystal X‐ray Detector
Author(s) -
Huang Yanmin,
Qiao Lu,
Jiang Yuanzhi,
He Tingwei,
Long Run,
Yang Fan,
Wang Lin,
Lei Xiaojuan,
Yuan Mingjian,
Chen Jun
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201911281
Subject(s) - detector , x ray detector , halide , density functional theory , materials science , figure of merit , single crystal , perovskite (structure) , coupling (piping) , crystal (programming language) , optoelectronics , nanotechnology , crystallography , chemistry , physics , optics , inorganic chemistry , computer science , computational chemistry , programming language , metallurgy
Metal halide perovskites have emerged as a new generation of X‐ray detector materials. However, large‐sized MAPbI 3 single crystals (SCs) still exhibit lower performance than MAPbBr 3 SCs in X‐ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large‐sized cations at the A site. The alloyed process could notably decrease the electron–phonon coupling strength and increase the material defect formation energy. Accordingly, centimeter‐sized alloyed DMAMAPbI 3 (DMA=dimethylammonium) and GAMAPbI 3 (GA=guanidinium) SCs are obtained. Electrical characterizations confirm the GAMAPbI 3 SCs display improved charge collection efficiency. It also exhibits a remarkable reduction of dark current, an important figure of merit for X‐ray detectors. With a judiciously designed device architecture, the overall detector performance confirms GAMAPbI 3 SCs as one of the most sensitive perovskite X‐ray detectors to date.