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.

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Photodetectors (PDs) are critical parts of visible light communication (VLC) systems for achieving efficient photoelectronic conversion and high-fidelity transmission of signals. Antimony sulfide (Sb2S3) as a nontoxic, high optical absorption coefficient, and low-cost semiconductor becomes a promising candidate for applications in VLC systems. Particularly, Sb2S3 PDs were verified to have significantly weak light detection ability in the visible region. However, the response speed of Sb2S3 PDs with existing device structures is still relatively slow. Herein, through optimizing the device structure for the p–i–n type PDs, a p-type Sb2Se3 hole transport layer (HTL) is designed to enhance the built-in electric field and to accelerate the migration of photogenerated carriers for the high responsivity and fast response speed. The optimal thickness of the structure is obtained through the simulation of SCAPS-1D software, and the optimized devices show high-performance parameters, including a responsivity of 0.34 A W–1, a specific detectivity (D * ) of 2.20 × 1012 Jones, the −3 dB bandwidth of 440 kHz, high stability, and the value of the Sb2S3 PDs can reach 60% in the range of 360–600 nm, which indicates that the device is very suitable for working in the visible light band. In addition, the resulting Sb2S3 PD is successfully integrated into VLC systems by designing a matched light detection circuit. The results suggest that the Sb2S3 PDs are expected to provide an alternative to future VLC system applications.