Optoelectronic properties of facile synthesized orthorhombic cesium lead bromide (CsPbBr₃)

CsPbBr₃ has been synthesized via a wet chemical technique instead of colloidal hot injection route. Crystalline structure and chemical composition of the material have been assured by Rietveld refinement and energy dispersive X-ray spectroscopy. Photoresponse capability of CsPbBr₃ nanocrystal in cubic phase has been already explored. Here, intrinsic optoelectronic properties of orthorhombic CsPbBr₃ have been investigated in detail. A prototype photodetector has been fabricated on a transparent conducting oxide-coated glass by using silver as the other electrode material. The photo-responsibility of CsPbBr₃ arises due to the combined effect of electron–hole pair generation and trapping within material and recombination. The non-linearity of I–V characteristics clearly reveals the formation of well-established Schottky contact at perovskite–ITO junction. Responsivity of the detector increases from 1.4 to 1.73 mA W⁻¹ after enhancing the irradiance from 25 to 100 mW cm⁻² at 8 V bias voltages. Linear dynamic range has been accounted to study the linear photosensitivity of the device. In order to investigate the stability and reversibility, photocurrent has been measured under ON/OFF condition of frequency 20 s. The quantitative contribution of polycrystalline grain and grain boundary to charge mobilization has been evaluated by fitting the Cole–Cole plot under different solar intensities.