Recent Progress in Silicon-Based On-Chip Integrated Infrared Photodetectors

Infrared (IR) photodetectors are indispensable to modern optoelectronic systems, ranging from night vision imaging, surveillance, and industrial process control to environmental monitoring and medical diagnostics. However, traditional detectors based on bulk semiconductors are constrained by prohibitive fabrication costs and the stringent requirement for bulky cryogenic cooling, which severely hinders their widespread deployment in Size, Weight, and Power (SWaP)-sensitive scenarios. Silicon-based on-chip integration, leveraging compatibility with mature CMOS processes, has emerged as a transformative paradigm. It enables the realization of fully functional photonic integrated circuits (PICs) capable of on-chip sensing and high-speed data transmission, offering a pathway toward miniaturized and cost-effective architectures. This article provides a review of recent progress in silicon-based infrared photodetectors across three core material systems: Group IV (Ge/GeSn), III-V compounds, and two-dimensional (2D) materials. In the end, we offer an outlook on the development trends of next-generation intelligent sensing systems driven by optoelectronic convergence.