Microconcave MAPbBr3 Single Crystal for High-Performance Photodetector.

We present the first report of a new suspension method for obtaining cubic MAPbBr3 single crystal with a concave surface. The cubic MAPbBr3 crystal with microconcavity possesses good crystallinity and carrier lifetime. Excellent photoelectric performance was provided by the concavity-based MAPbBr3 photodetectors because of the good light trapping and shortened carrier pathway. As a result, the concavity-based photodetector exhibits superior responsivity of 62.9 and 5.43 A W-1 and EQE of 1.50 × 104% and 1.30 × 103% under low-power and high-power 520 nm irradiation 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 the plane-based photodetector. In particular, the concavity-based photodetector has an ultrahigh detectivity of 6.5 × 1012 Jones at ultralow power of 3.67 μW cm-2, which is 6.5 times higher than that of the planar device.