Advances in Silicon-Based UV Light Detection

Silicon (Si), the cornerstone semiconductor in the micro-electronics industry, can provide a cost-efficient platform with mature technologies for photodetection in visible and near-infrared regions. However, its intrinsic properties, such as a narrow bandgap and the shallow penetration depth of ultraviolet (UV) light into its surface with surface trap states, remain challenges, rendering it unsuitable for effective UV light detection. Various techniques have been reported to circumvent these surface defect-induced difficulties. In addition, wide-bandgap semiconductors that favor UV light absorption in a solar-blind way have been combined with Si for UV light detection in order to retain the device's compatibility with Si-CMOS processes, though it still faces challenges that need to be overcome. This review starts with concepts of basic parameters of photodetectors and categorizes UV photodetectors according to their detection mechanisms. We also present a review of wide-bandgap semiconductor-based UV light detectors and those based on Si, with a discussion of surface defect minimization. In addition, we review the hybrid structure of the two kinds, i.e., wide-bandgap semiconductors and Si, and discuss their properties that produce synergistic effects. Lastly, we provide conclusions and outlooks for the possible development of next-generation UV light detectors based on Si.