Search

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]

Methylammonium lead bromide (MAPbBr3) single crystal thin film shows great opportunities in high‐performance optoelectronic devices due to its high absorption coefficient, high photoelectric conversion efficiency, and low trap‐state density properties. In order to fabricate a highly sensitive self‐powered photodetectors, herein, a MAPbBr3 single crystal thin film/molybdenum disulfide (MoS2) vertical p‐n heterostructure based photodetector has been built by typical polymer film assisted dry transfer method and micromachining technique. Attributing to the built‐in electric field and the shortened transmit distance for the photogenerated carriers in this heterostructure, the device shows excellent photovoltaic characteristics with a maximum output electrical power of 7 nW and power conversion efficiency of 8% at 0.34 V under 532 nm laser. Moreover, prominent photoelectric properties with responsivity of 368 mA W−1 and detectivity of 3.74 × 1012 Jones for 532 nm laser without any bias have been achieved, which are ranking high among the organic–inorganic hybrid perovskites based self‐power photodetectors. These results demonstrate that the MAPbBr3 single crystal thin film/MoS2 vertical heterostructure can pave a new way to develop high‐performance photovoltaic devices. [ABSTRACT FROM AUTHOR]