Tailoring performance of perovskite-based tunneling photodetector for portable monitoring of ultraviolet radiation risk

Portable sensing systems have a broad application prospect in the field of personal healthcare via continuous monitoring of surroundings. Ultraviolet (UV) light, deemed to be a main inducement of skin-related cancers, calls for the development of UV detectors with properties of high sensitivity and portability. Herein, we constructed a CsPbCl3 film-based tunneling UV sensor (CTUS) based on the photo-induced tunneling mechanism. By optimizing the thickness of the tunneling layer inserted through an atomic layer deposition process, dark current of the CTUS was suppressed by three orders of magnitude, thus obtaining a salient UV detecting performance (ultralow dark current of 100 pA, high responsivity of 285 mA/W, broad linear dynamic range of 95 dB, fast response time of 2.1 μs, and weak light detection limit of 150 nW), which is comparable to the commercial Si-based PIN-type UV detectors. A UV wristband was further built by merging the CTUS with a self-designed flexible printed circuit board. Co-assisted by a self-developed APP, real-time and continuous monitoring of sun radiation to prevent diseases due to excessive sunburn was demonstrated. The proof-of-concept system will pave the way for portable device development, thus bridging the gap between technology innovation and real life.