Recent Advances in Colloidal Quantum Dots-Based Shortwave Infrared Photodetectors

Abstract

The growing demand for shortwave infrared (SWIR) technologies, such as object recognition and monitoring, autonomous systems, and biomedical imaging, has increased interest in next-generation SWIR photodetectors that feature high performance and cost-effective fabrication. Current SWIR photodetectors are dominated by epitaxial semiconductor materials such as indium gallium arsenide (InGaAs) and germanium (Ge), which require an expensive fabrication process. Colloidal quantum dots (CQDs) based on IV–VI, III–V, and I–VI materials offer a solution-processable and cost-effective alternative. Their size-tunable optical properties and compatibility with large-area fabrication make CQDs a commercially viable platform for SWIR photodetectors. To enhance the performance of CQD-based photodetectors, various strategies have been applied to the overall fabrication processes, including CQD synthesis, ligand exchange, and device engineering. As a result, CQD-based photodetectors are increasingly being integrated into system-scale applications, such as multispectral imaging and time-of-flight (ToF) sensors. This review showcases the recent advances in CQD photodetectors from material design to device fabrication and discusses the challenges and prospects for IR applications.