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

Abstract

Band gap tunable hybrid organic–inorganic lead halide perovskites (APbX 3, A = CH 3 NH 3 + and NH 2 CH═NH 2 +, 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 CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3, were certified to be advantageous over thin films as photodetectors. However, their resistance toward heat and moisture hinders their future development. Fully inorganic perovskite CsPbBr 3 stands a chance to fill the gap as a novel photodetector with perovskite structure. We revealed the growth of CsPbBr 3 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 CsPbBr 3 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.