Self-Powered Ultraviolet Sensor Based on CsPbCl₃ for Skin Safety Monitoring

Extended exposure to ultraviolet (UV) radiation significantly increases the risk of skin cancer. The World Health Organization reports that when the UV index surpasses 7, the skin becomes vulnerable to diseases like erythema. There is an urgent need for an UV photodetector capable of real-time UV intensity monitoring. In recent years, cesium lead chloride (CsPbCl₃) has emerged as a superior candidate material in the field due to its wide bandgap of 2.8 eV and outstanding UV optoelectronic and ferroelectric performance. In this study, a self-powered CsPbCl₃ thin-film photodetector was fabricated by a two-step spin-coating method along with a seven-level UV detection system. When the UV level reaches or exceeds level 7, the device sends a warning via Wi-Fi, enabling individuals to take prompt protective measures against harmful UV radiation. Additionally, the potential of the detector for optical imaging was demonstrated by reconstructing the image of the letters "UJS" using single-pixel imaging techniques. The findings indicate that the self-powered CsPbCl₃ UV photodetector holds substantial promise for skin health management and optical imaging.