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Due to the inherent high dark current of photoelectrochemical (PEC)‐type photodetectors (PDs), there is a tricky challenge to detect weak light. In this work, high‐quality Cd0.9Pb0.1Se quantum dots (CPS QDs) are prepared by thermal injection method, with horizontal size of 6.3 nm and thickness of 3.5 nm. The CPS QDs are directly utilized to construct the working electrode of PEC‐type PDs. The effects of experimental parameters on the photo‐response behavior are systematically studied, and optimized photocurrent density of 7.1 µA cm−2 and photo‐responsivity (Rph) of 2.75 mA·W−1 are achieved. Most importantly, the obvious photocurrent signals are observed under a light power density as low as 5.6 µW cm−2. For this interesting weak light detection, apparent Rph of 6.96 mA·W−1, detectivity of 1.2 × 109 Jones, and external quantum efficiency of 2.37% are achieved. Therefore, this work not only develops CPS QDs‐based PDs but also provides an example for PEC‐type PDs in weak light detection. [ABSTRACT FROM AUTHOR]

In recent decades, quantum dots (QDs) with tunable bandgap, large absorption coefficient, high quantum yield, multiexciton effect, and easy solution processing have unparalleled advantages in photoelectric conversion. Optoelectronic devices based on QDs of different composition have made great progress. However, there is still a lack of reviews on comparing the optoelectronic application level of semiconductor quantum dots (SQDs), perovskite quantum dots (PQDs), and carbon quantum dots (CDs), and also rarely providing a comprehensive summary of photocatalysis. First, this review almost completely summarizes advantages and disadvantages of common synthesis methods for QDs, especially pointing out the importance of optimization strategies for preparing high‐quality QDs such as ligand engineering, ion exchange, and purification separation. Then, compositions of SQD, PQD, CD, and corresponding optoelectronic properties are introduced, respectively. Next, the strengths and weaknesses of the four QDs structures are compared in detail. Finally, the flourishing development in various optoelectronic applications is separately demonstrated, and development degree of SQDs, PQDs, and CDs is compared to discover the most suitable application scenarios for each. On these bases, bottlenecks and opportunities are also put forwarded, hoping to stimulate more breakthroughs in this field. [ABSTRACT FROM AUTHOR]

Undoubtedly, SARS-CoV-2 has caused an outbreak of pneumonia that evolved into a worldwide pandemic. The confusion of early symptoms of the SARS-CoV-2 infection with other respiratory virus infections made it very difficult to block its spread, leading to the expansion of the outbreak and an unreasonable demand for medical resource allocation. The traditional immunochromatographic test strip (ICTS) can detect one analyte with one sample. Herein, this study presents a novel strategy for the simultaneous rapid detection of FluB/SARS-CoV-2, including quantum dot fluorescent microspheres (QDFM) ICTS and a supporting device. The ICTS could be applied to realize simultaneous detection of FluB and SARS-CoV-2 with one test in a short time. A device supporting FluB/SARS-CoV-2 QDFM ICTS was designed and had the characteristics of being safe, portable, low-cost, relatively stable, and easy to use, ensuring the device could replace the immunofluorescence analyzer in cases where there is no need for quantification. This device does not need to be operated by professional and technical personnel and has commercial application potential. [ABSTRACT FROM AUTHOR]