Recent Advances of Colloidal Quantum Dot Photodetectors for Emerging Optoelectronic Applications

ABSTRACT With the development of information technology, photodetectors as critical components of optoelectronics have demonstrated significant potential applications in image sensors, wearable optoelectronics, and machine visual systems. Solution‐processed colloidal quantum dots (CQDs) have attracted dramatic attention in emerging optoelectronics due to their unique characteristics from quantum effects, including strong light absorption with full‐spectrum, size‐dependent bandgap, tuneable electronic and optical properties, and compatibility with a range of substrates, enabling the fabrication of low‐cost, large‐area, and flexible devices. Herein, we review the developments in CQD photodetectors and their applications in emerging optoelectronics. First, the fundamentals of CQDs are introduced, including quantum confinement, size‐dependent bandgap, and the solution‐processed synthesis and assembly techniques. Then, the basic principles and recent advancements in CQD photodetectors are reviewed, specifically highlighting strategies for improving device performance, such as surface engineering, interface engineering, and energy band engineering. More importantly, emerging optoelectronic applications are summarized, including image sensors, wearable health monitoring, and artificial visual systems. Finally, we deliver the conclusions and discuss the challenges and future development trends of CQD‐based optoelectronics. This review aims to provide a systematic understanding and valuable insights into CQD photodetectors to satisfy the practical requirements of future emerging applications.