Exploring Cinnabar: A Natural Resource for Self‐Powered Electrochemical Photodetector Application

Abstract This study investigates cinnabar (HgS) as a material for self‐powered electrochemical photodetection, addressing the challenges of high‐power consumption and inefficient charge transfer in conventional photodetectors. Current photodetector technologies often rely on external biasing, which limits their energy efficiency and applicability in remote sensing. In contrast, this work demonstrates that cinnabar‐based devices exhibit self‐powered functionality, eliminating the need for external power sources. Characterization techniques, such as X‐ray diffraction and optical response measurements reveal high crystallinity, a hexagonal crystal structure, and a UV–visible absorption with a 2 eV band gap making cinnabar a strong light‐harvesting material. Photoluminescence analysis shows near‐white light emission, enhancing its potential in optical sensing. Thermogravimetric analysis highlights phase transitions from α HgS to β HgS, indicating thermal stability crucial for long‐term device performance. Electrochemical tests including cyclic voltammetry, confirm efficient charge transfer which is essential for photodetection. Notably, cinnabar‐based photodetectors exhibit self‐powered operation with optimal photocurrent at 0 V bias, demonstrating rapid response, high responsivity, and enhanced stability. These results position cinnabar as a promising material for energy‐efficient, next generation photodetection technologies, with potential applications in imaging, sensing, and optical communication.