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In this paper, a performance-enhanced hybrid ultraviolet metal–semiconductor–metal photodetector (UVPD) has been produced. This device incorporates a mixed photosensitive layer consisting of MXene nanoflakes that are covered on a thin film formed by Ag nanowires (NWs) wrapped in ZnO nanoparticles. This configuration, referred to as ZnO@Ag NWs/Mxene, capitalizes on the hot electrons generated by the localized surface plasmon resonance phenomenon occurring in the Ag NWs and MXene. These hot electrons possess sufficient energy to traverse the interface depletion layer and reach the ZnO layer. Therefore, the injected hot electrons serve as additional photo carriers in the ZnO layer, thereby increasing the number of photo-generated carriers and improving the carrier concentration in ZnO. The improved UVPD device exhibits an amplified photocurrent of ∼2499.35 nA at 5 V, under a light intensity of 6.52 mW cm−2 and a wavelength of 365 nm. Simultaneously, it achieves enhanced performance indices, including an On/Off ratio of ∼984.19, a responsivity (R p) of ∼66.87 mA W−1, and a detectivity (D *) of ∼1.82 × 1011 jones. These values represent a significant improvement compared to devices based solely on the ZnO configuration, with enhancements of ∼24.90, 3.93, 23.38, and 9.33 times, respectively. Based on the obtained results, it can be inferred that employing the hot electron injection effect to design and enhance the performance of optoelectronic devices based on wide band gap semiconductors is a reasonable and effective strategy. [ABSTRACT FROM AUTHOR]

Perovskite single crystals (SCs) have gained significant interest in various applications owing to their superior optoelectrical and physical characteristics as compared to polycrystalline films. However, a considerable portion of incident light is typically reflected at the surface of perovskite SCs, leading to insufficient light absorption within the crystal bulk, ultimately resulting in reduced performance of SC‐based photodetectors. In the present work, an inverted pyramid‐shaped structure is in situ introduced on the surface of an MAPbBr3 SC during the crystal growth process, which can reduce light reflection in the surface region and enhance light absorption of the SC. Additionally, the hydrophobic small molecule copper (II) phthalocyanine (CuPc) is thermally evaporated onto the SC, forming a CuPc/MAPbBr3 heterojunction for the first time. The CuPc/pyramid‐shaped MAPbBr3 heterojunction‐based photodetector exhibits self‐powered characteristics and superior optoelectrical performance, achieving a photocurrent of greater than 10−5 A (10−7 A), a responsiveness of 257 mA W−1 (8.84 mA W−1), and a detection rate of 2.98 × 1012 Jones (1.02 × 1011 Jones) at −2 V (0 V) bias. Simultaneously, the device demonstrates excellent long‐term stability under high humidity conditions, retaining 90.5% of its initial photocurrent even after 60 days in a 60–80% humidity environment. [ABSTRACT FROM AUTHOR]

Compared with polycrystalline films, perovskite single crystal is considered as a promising photoelectric material due to its unique advantages in quantum efficiency and carrier diffusion length. In this work, the micron-thickness MAPbBr3 single crystal was prepared through a highly repeatable process based on the crystal seed dissolution-growth method. A heterojunction of MAPbBr3/WO3 single crystal was realized through a simple thermal evaporation process, and the integrated C/MAPbBr3/WO3/C device demonstrated self-powered characteristics and high photoelectric performance, which showed good responsivity of about 111 mA/W, detectivity of 9.64×1011 Jones and fast response speed (0.11/0.56 ms). Meanwhile, the device exhibited good rectification performance (ratio of 125 at ±2 V) and reduced dark current due to the built-in electric field formed in the heterojunction. This study provides a facile, flexible, and highly repeatable method for the preparation of high-performance photodetectors based on MAPbBr3 single crystals with micrometer thickness. [ABSTRACT FROM AUTHOR]

Heterojunctions were widely studied as semiconductor structures for photoelectronic devices such as solar cells and photodetectors, due to their ability for dark current reduction and self-powered operation. In this work, an α-FAPbI3/MAPbI3 single crystal concentric annular lateral heterojunction was successfully fabricated by liquid phase epitaxy under ambient conditions. Compared to a vertical heterojunction structure, a lateral structure can reduce the incident light loss and interfacial accumulation of defects. In addition, the selection of the same halogen sites can resolve the issue of phase separation stemming from different halogen ions in the perovskite materials. By fabricating an α-FAPbI3/MAPbI3 single crystal concentric annular lateral heterojunction, a wide spectrum response from ultraviolet to near-infrared is attained. Furthermore, depending on the reduction of the potential barrier due to the pyro-phototronic effect generated by the MAPbI3 single crystals and the presence of the built-in electric field, the α-FAPbI3/MAPbI3 single crystal lateral heterojunction-based photodetector exhibits a high responsivity of 27.50 mA W−1, a specific detectivity of 7.71 × 1011 Jones, a fast response speed of 62.7 μs and self-powering ability. These results suggest that lateral perovskite single crystal heterojunctions with the same halogen are promising configurations for photodetectors and other optoelectronic devices and systems. [ABSTRACT FROM AUTHOR]