Short‐Wave Infrared Photodetectors and Imaging Sensors Based on Lead Chalcogenide Colloidal Quantum Dots

Lead chalcogenide quantum dots (QDs) are one of the next generations of ideal narrow bandgap infrared semiconductors, due to their succinct solution processing, low-cost fabrication, size-tunable infrared bandgap, and excellent optoelectronic properties. Tremendous efforts including synthesis methods, surface ligand engineering, and device architecture engineering, drastically contribute to the significant improvement of the performance of the photodetectors based on QDs. In recent years, with the rapid development of consumer electronics, short-wave infrared (SWIR) imaging sensors are in urgent demand. Thanks to the flexible manipulation of the QD thin film deposition process, a variety of QD-based imaging technologies have been studied, including single-pixel imaging sensors, integrated imaging sensors with readout circuit, and upconversion imaging sensors, which can effectively reduce the cost of SWIR imaging sensors and promote the commercial application in the consumer electronics. Herein, recent advances of QD-based photodetectors and imaging sensors are summarized, emphatically focusing on the synthesis of QDs, surface ligand engineering, device architecture engineering, and imaging technology.