Self-Powered X-Ray Photodetector Based on Ultrathin PbI2 Single Crystal

Abstract

Lead iodide (PbI2) single crystals have been extensively investigated due to their potential applications in nuclear radiation detectors at room temperature. In this letter, the properties of ultrathin PbI2 single crystals were obtained and investigated by X-ray diffraction, ultraviolet-visible diffuse reflection spectroscopy, and field emission scanning electron microscopy. The X-ray photodetector based on ultrathin PbI2 single crystal with a Schottky configuration of Au/PbI2/Mo was also fabricated through a facile method. Especially, the X-ray photodetector exhibits good stability and reproducibility. A large sensitivity of ${0}.{12} \times {10}^{{4}} \mu \text{C}$ /Gyair/cm2 was obtained for X-ray photodetector based on PbI2 single crystal at zero bias under a low radiation dose rate (0.19 mGy/h), which is sixty times higher than that of currently $\alpha $ -Se X-ray detectors at high bias. Moreover, we have further illustrated the working principles of the photodetector at zero, positive and negative bias with and without X-ray illumination. Our investigation substantiates the potential of the self-powered X-ray photodetector based on ultrathin PbI2 single crystal as a candidate device in optoelectronic applications.