Micro-Concave MAPbBr3 Single Crystal for High-Performance Photodetector.

We report a new suspension method to obtain the cubic MAPbBr3 single crystal with a concave surface for the first time. The cubic MAPbBr3 crystal with micro-concavity possesses the good crystallinity and carrier lifetime. The excellent photoelectric performance was provided by the concave based MAPbBr3 photodetectors due to the good light trapping and shortened carrier pathway. As a result, the concave-based photodetector exhibits the superior responsivity of 62.9 A W-1 and 5.43 A W-1 and EQE of 1.50×104% and 1.30×103% under low-power and high-power 520 nm irradiations of 3.67 μW cm-2 and 35.4 mW cm-2 at 3 V respectively, which are more than 500% higher than those of plane-based photodetector. Especially, the concave based photodetector has an ultrahigh detectivity of 6.5×1012 Jones at ultralow power of 3.67 μW cm-2, 6.5 times as high as that of the planar device.