Microconcave MAPbBr Single Crystal for High-Performance Photodetector.

We present the first report of a new suspension method for obtaining cubic MAPbBr single crystal with a concave surface. The cubic MAPbBr crystal with microconcavity possesses good crystallinity and carrier lifetime. Excellent photoelectric performance was provided by the concavity-based MAPbBr 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 and EQE of 1.50 × 10% and 1.30 × 10% under low-power and high-power 520 nm irradiation of 3.67 μW cm and 35.4 mW cm 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 × 10 Jones at ultralow power of 3.67 μW cm, which is 6.5 times higher than that of the planar device.