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

Lead iodide (PbI
₂
) 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 PbI
₂
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 PbI
₂
single crystal with a Schottky configuration of Au/PbI
₂
/Mo was also fabricated through a facile method. Especially, the X-ray photodetector exhibits good stability and reproducibility. A large sensitivity of 0.12 × 10
⁴
μC/Gy
_air
/cm
²
was obtained for X-ray photodetector based on PbI
₂
single crystal at zero bias under a low radiation dose rate (0.19 mGy/h), which is sixty times higher than that of currently α-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 PbI
₂
single crystal as a candidate device in optoelectronic applications.