Abstract: UV-visible broadband light harvesting ability is critical for photodetectors, and all inorganic perovskite CsPbBr₃ is regarded as a promising candidate as the response active material. Herein, a saturated-solution crystallization method is employed to synthesize CsPbBr₃ single crystal. Temperature-dependent photoluminescence spectra with one-photon and two-photon excitation are systematically investigated, determining a large exciton binding energy of 39.8 meV. This allows the stable excitonic emission of CsPbBr₃ single crystal at room temperature. Subsequently, an asymmetric structure CsPbBr₃ photodetector is fabricated by using InGa alloy as the Ohmic electrode and Au as the Schottky electrode. At -8 V, the device exhibits a prominent response to the irradiation from UV to green band with a maximum responsivity of 2.56 A/W, an external quantum efficiency of 580 %, and a detectivity of 1.24 ×; 10¹³ Hz^1/2 W^-1. In addition, the CsPbBr₃ photodetector also presents rapid response speeds at both reverse and forward bias voltages and self-powered characteristics owing to the Schottky depletion layer underneath the Au electrode. The demonstration of asymmetric metal-semiconductor-metal (MSM) structure photodetector presents a promising pathway toward next-generation CsPbBr₃ optoelectronic devices.

Key words: Room temperature, CsPbBr₃, Single crystal, Asymmetric Photodetector