High Detectivity and Rapid Response in Perovskite CsPbBr₃ Single-Crystal Photodetector

Abstract

Band gap tunable hybrid organic–inorganic lead halide perovskites (APbX3, A = CH3NH3+ and NH2CH═NH2+, and X = Cl, Br, or I) have attracted significant attention in optoelectronic- and photovoltaic-related fields on account of their outstanding optoelectronic properties. Single crystals of hybrid perovskites, such as CH3NH3PbI3 and CH3NH3PbBr3, were certified to be advantageous over thin films as photodetectors. However, their resistance toward heat and moisture hinders their future development. Fully inorganic perovskite CsPbBr3 stands a chance to fill the gap as a novel photodetector with perovskite structure. We revealed the growth of CsPbBr3 single crystal was of a 2D nucleation mechanism. Similarities of d values and octahedra arrangements along [101] and [020] orientations restricted single-crystal growth. Under optimized conditions, orthorhombic CsPbBr3 single crystals with (101) crystallographic facets were grown by using methyl alcohol as antisolvent from saturated DMSO solution. The optoelectronic properties of the single crystal were explored through a metal–semiconductor–metal photodetector device. Meanwhile, their steady and transient performances were also investigated. A highest responsivity of 0.028 A/W and a response time of <100 ms were achieved.