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Two-dimensional layered metal dichalcogenides have given rise to considerable interest in electronics and optoelectronics fields because of their excellent physical and chemical properties and promising applications. Tin disulfide (SnS2) is an important member of them due to its environment-friendly and resource-rich characteristics. Here, a series of in situ electrical transport experiments and photocurrent measurements under high pressure have been performed to investigate the electrical and opto-electrical properties of 4H-SnS2. With increasing pressure, the electrical resistivity of 4H-SnS2 decrease significantly, leading to a transition from semiconducting to metallic state above 58.6 GPa. The increase in pressure results in a substantial enhancement in photoelectric activity, indicating the extensive potential of utilizing pressure as a trigger for in situ optoelectronic applications. Combined with our previous results of x-ray diffraction and optical absorption at high pressure, pressure-induced structural distortion, bandgap narrowing, metallization, and enhancement of photoelectric activity of 4H-SnS2 are tunable and reversible, which are of great significance for both fundamental research and device design. [ABSTRACT FROM AUTHOR]

Photoelectric devices based on the photothermoelectric (PTE) effect show promising prospects for broadband detection without an external power supply. However, effective strategies are still required to regulate the conversion efficiency of light to heat and electricity. Herein, significantly enhanced photoresponse properties of PbI2 generated from a PTE mechanism via a high‐pressure strategy are reported. PbI2 exhibits a stable, fast, self‐driven, and broadband photoresponse at ≈980 nm. Intriguingly, the synergy of the photoconductivity and PTE mechanism is conducive to enhancing the photoelectric properties, and extending the detection bandwidth to the optical communication waveband (1650 nm) with an external bias. The dramatically enhanced photoresponse characteristics are attributed to narrowing of the band gap and a significantly decreased resistance, which originate from the enhancement of atomic orbital overlap owing to pressure‐induced Pb‐I bond contraction. These findings open up a new avenue toward designing self‐driven and broadband photoelectric devices. [ABSTRACT FROM AUTHOR]

Photoelectric devices based on the photothermoelectric (PTE) effect show promising prospects for broadband detection without an external power supply. However, effective strategies are still required to regulate the conversion efficiency of light to heat and electricity. Herein, significantly enhanced photoresponse properties of PbI2 generated from a PTE mechanism via a high‐pressure strategy are reported. PbI2 exhibits a stable, fast, self‐driven, and broadband photoresponse at ≈980 nm. Intriguingly, the synergy of the photoconductivity and PTE mechanism is conducive to enhancing the photoelectric properties, and extending the detection bandwidth to the optical communication waveband (1650 nm) with an external bias. The dramatically enhanced photoresponse characteristics are attributed to narrowing of the band gap and a significantly decreased resistance, which originate from the enhancement of atomic orbital overlap owing to pressure‐induced Pb‐I bond contraction. These findings open up a new avenue toward designing self‐driven and broadband photoelectric devices. [ABSTRACT FROM AUTHOR]

Constantly exploring and improving the photoelectric properties of functional materials is of paramount importance for the development of the optoelectronics industry. Herein, a new strategy to extend the spectral response range and enhance the photoelectric properties of functional materials using high pressure is presented. In addition, the successful application of this strategy to the regulation of the photoelectric properties of 2D layered semiconductor iodine is reported. The maximum photocurrent is four orders of magnitude higher than that measured under initial pressure, with visible‐light illumination. Impressively, the light‐response range of iodine is successfully extended to the near‐infrared (1064 nm) with the application of pressure, and the photoresponse properties are also significantly enhanced with compression. These dramatically enhanced photoelectric activities are attributed to charge delocalization as well as an increased charge density in the regions between parallel molecules, which occur as a result of pressure‐induced charge transfer in the iodine molecules. These findings can be extended to guide the modification of the spectral response range and photoelectric properties of other functional materials. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid perovskites with well-defined morphology have attracted much attention due to their unique photophysical properties. However, controlling the morphology of nanocrystalline perovskite to improve its photoelectric application remains a challenge. In this article, using a modified solution deposition method, we successfully synthesized uniform methylammonium lead iodide (MAPbI3) nanoplates, nanocubes, and nanorods and investigated the effect of morphology on the photoelectric properties of these materials. We found that the morphology can be controlled by regulating the amounts of reactant methylammonium iodide (MAI) and the rate at which MAPbI3 precursor is added into toluene solution, and that the corresponding size distributions can be optimized by tuning the final vacuum-drying temperature. The morphology has an obvious effect on the bandgap optimization and fluorescence enhancement of MAPbI3, and the nanoplates exhibit stronger photoluminescence intensity and have a longer carrier lifetime than nanocubes and nanorods. The results show that the morphologies of MAPbI3 perovskite nanocrystals can be controlled by tuning the synthesizing conditions, and the MAPbI3 perovskite nanocrystals with special morphology can be used in special nanosize optoelectronic devices. [ABSTRACT FROM AUTHOR]

The development of the optoelectronics industry relies on the constant exploration and improvement of the photoelectric properties of functional materials. Responsivity and response speed are two key performance indicators of photodetectors. However, these parameters are often mutually suppressed, and ensuring both simultaneously is challenging. Herein, we developed a viable strategy to enhance the overall photodetection performance by applying pressure to improve both the photoresponsivity and the response speed of BiOBr simultaneously. The results showed that the responsivity of BiOBr at a pressure of 3.8 GPa was more than an order of magnitude higher than that measured at the initial pressure (0.2 GPa) under Xenon-light illumination. More importantly, the response speed of BiOBr was improved by almost an order of magnitude under 3.7 GPa and 405 nm laser illumination. The considerably enhanced photoresponsivity and photoresponse speed suggest that pressure effectively reduces the effective mass of carriers and promotes charge transfer between Bi-O atoms. Our findings reveal that comprehensive enhancement of optoelectronic properties in layered compounds can be achieved through pressure modulation of the electronic structure, providing a promising approach for materials design toward extraordinary properties. [Display omitted] [ABSTRACT FROM AUTHOR]