Recently, low-dimensional organic−inorganic lead halide perovskites have attracted a great deal of attention due to their outstanding tunable broadband emission, while the toxicity of lead hinders their further application in the photoelectric field.Here, we report a novel lead-free Cu(I)-based organic−inorganic perovskite-related material of a (MA) 4 Cu 2 Br 6 single crystal with zero-dimensional clusters, which is a unique Cu 2 Br 6 4− cornersharing tetrahedron dimer structure consisting of two connected tetrahedra. The single crystal displays a bright broadband green emission with a high photoluminescence with a quantum yield of ≤93%, a large Stokes shift, and a very long (microsecond) photoluminescence (PL) lifetime, resulting from self-trapped exciton emission. The direct band gap characteristic of (MA) 4 Cu 2 Br 6 was proven by density functional theory calculation, and its band gap was determined by experiments to be ∼3.87 eV. In the temperature range of 98−258 K, the PL intensity increases gradually with an increase in temperature due to the deep trapping out of strong electro-phonon coupling, while the PL decreases when the temperature increases over 258 K due to phonon scattering. It is worth mentioning that this new material has high chemical and light stability, in contrast to the lead perovskite.

Pb-free perovskite materials, C8H20N2MnBr4 and C4H10NMnBr3 with high luminescence yields, were obtained via a simple mechanochemical process.

Currently, colloidal quantum dots (CQDs)-based photodetectors are widely investigated due to their low cost and easy integration with optoelectronic devices. The requirements for a high-performance photodetector are a low dark current and a high photocurrent. Normally, photodetectors with a low dark current also possess a low photocurrent, or photodetectors with reduced dark current possess a reduced photocurrent, resulting in low detectivity. In this paper, a solution to suppress dark current and maintain a high photocurrent, i.e., use of poly­(methyl methacrylate) doped with Au nanoparticles (NPs) (i.e., PMMA:Au) as an interlayer for enhanced-performance tandem photodetectors, is presented. Our experimental data showed that the dark current through the tandem photodetector ITO/PEDOT:PSS/PbS:CsSnBr3/ZnO/PMMA:Au/CuSeN/PbS:CsSnBr3/ZnO/Ag is suppressed significantly; meanwhile, a high photocurrent is maintained after a PMMA:Au interlayer has been inserted between two subdetectors. The inserted PMMA:Au interlayer acts as storage nodes for electrons, reducing the dark current through the device; meanwhile, the photocurrent can be enhanced under illumination. As a result, the specific detectivity of the tandem photodetector with 35 nm PMMA:Au interlayer was enhanced significantly from 5.01 × 1012 to 2.7 × 1015 Jones under 300 μW/cm2 532 nm illumination at a low voltage of −1 V as compared to the device without a PMMA:Au interlayer. Further, the physical mechanism of enhanced performance is discussed in detail.

Commercial photodetectors based on silicon are extensively applied in numerous fields. Except for their high performance, their maximum absorption wavelength is not over than 1100 nm and incident light with longer wavelengths cannot be detected; in addition, their cost is high and their manufacturing process is complex. Therefore, it is meaningful and significant to extend absorption wavelength, to decrease cost, and to simplify the manufacturing process while maintaining high performance for photodetectors. Due to the properties of size-dependent bandgap tunability, low cost, facile processing, and substrate compatibility, solution-processed colloidal quantum dots (CQDs) have recently gained significant attention and become one of the most competitive and promising candidates for optoelectronic devices. Among these CQDs, lead chalcogenide CQDs are getting very prominent and are widely investigated. In this paper, the recent progress of infrared (IR) photodetectors based on lead sulfide (PbS), lead selenide (PbSe), and ternary PbS x Se 1−x CQDs, and their underlying concepts, breakthroughs, and remaining challenges are reviewed, thus providing guidance for designing high-performance quantum-dot IR photodetectors.

In general, the fabrication of high‐performance, self‐powered broadband photodetectors based on traditional semiconducting thin films is tedious and costly. Here, in this paper a high‐performance, solution‐processed, and self‐powered CH3NH3PbI3 (MAPbI3) nanocrystal based photodetector ITO/MAPbI3/Ag is presented, and it shows broadband photoresponse from the visible to the near‐infrared wavelength region. The pronounced enhanced performance of the photodetector is due to taking the advantage of the built‐in electric field induced by the work function difference of two electrodes. The optimized photodetector shows a responsivity of 4.9 and 1.42 A W−1 with a specific detectivity of 7.6 × 1013 and 1.77 × 1013 Jones under 19 µW cm−2 white light illumination and 26 µW cm−2 808 nm illumination at zero bias, respectively. Therefore, such a concept of simple device geometry and feasible technique will open up a new and promising avenue for the fabrication of self‐powered photodetectors and the development of imaging devices.