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In recent years, 2D layered materials have been considered as promising photon absorption channel media for next-generation phototransistors due to their atomic thickness, easily tailored single-crystal van der Waals heterostructures, ultrafast optoelectronic characteristics, and broadband photon absorption. However, the photosensitivity obtained from such devices, even under a large bias voltage, is still unsatisfactory until now. In this paper, high-sensitivity phototransistors based on WS2 and MoS2 are proposed, designed, and fabricated with gold nanoparticles (AuNPs) embedded in the gate dielectric. These AuNPs, located between the tunneling and blocking dielectric, are found to enable efficient electron trapping in order to strongly suppress dark current. Ultralow dark current (10−11 A), high photoresponsivity (1090 A W−1), and high detectivity (3.5 × 1011 Jones) are obtained for the WS2 devices under a low source/drain and a zero gate voltage at a wavelength of 520 nm. These results demonstrate that the floating-gate memory structure is an effective configuration to achieve high-performance 2D electronic/optoelectronic devices. [ABSTRACT FROM AUTHOR]

An efficient ferroelectric-enhanced side-gated single CdS nanowire (NW) ultraviolet (UV) photodetector at room temperature is demonstrated. With the ultrahigh electrostatic field from polarization of ferroelectric polymer, the depletion of the intrinsic carriers in the CdS NW channel is achieved, which significantly reduces the dark current and increases the sensitivity of the UV photodetector even after the gate voltage is removed. Meanwhile, the low frequency noise current power of the device reaches as low as 4.6 × 10−28 A2 at a source-drain voltage Vds = 1 V. The single CdS NW UV photodetector exhibits high photoconductive gain of 8.6 × 105, responsivity of 2.6 × 105 A W−1, and specific detectivity ( D*) of 2.3 × 1016 Jones at a low power density of 0.01 mW cm−2 for λ = 375 nm. In addition, the spatially resolved scanning photocurrent mapping across the device shows strong photocurrent signals near the metal contacts. This is promising for the design of a controllable, high-performance, and low power consumption ultraviolet photodetector. [ABSTRACT FROM AUTHOR]

Correlated vanadium dioxide (VO2) has shown promises in functional materials and advanced electronic devices with outstanding metal–insulator transition (MIT). The manipulations of MIT and structural phase transition in correlated oxides are among the major challenges in both fundamental science and technological applications. Herein, the modulation of MIT behaviors in one VO2 nanowire with an artificial oxidized domain induced by selected‐area chemical nanoengineering is described. The formation of an artificial oxidized domain enables to suppress MIT and stabilize the insulating phase above the MIT temperature of pristine VO2 nanowires, which leads to an enhanced MIT hysteresis and temperature. The creation of artificial domains and the modulation of MIT in correlated oxide nanowires help to both investigate the essential physics behind correlated nanomaterials and fabricate nanoscale multifunctional devices. [ABSTRACT FROM AUTHOR]