UV-Assisted Photochemical Synthesis of Reduced Graphene Oxide/ZnO Nanowires Composite for Photoresponse Enhancement in UV Photodetectors

Abstract

The weak photon absorption and high recombination rate of electron-hole pairs in disordered zinc oxide nanowires (ZNWs) limit its application in UV photodetection. This limitation can be overcome by introducing graphene sheets to the ZNWs. Herein we report a high-performance photodetector based on one-dimensional (1D) wide band-gap semiconductor disordered ZNWs composited with reduced graphene oxide (RGO) for ultraviolet (UV) photoresponse enhancement. The RGO/ZNWs composites have been successfully synthetized through UV-assisted photochemical reduction of GO in ZNWs suspension. The material characterizations in morphology, Raman scattering, and Ultraviolet-visible light absorption verified the formation of graphene sheets attached in ZNWs network and the enhancement of UV absorption due to the introduction of graphene. In comparison with photodetectors based on pure ZNWs, the photodetectors based on RGO/ZNWs composite exhibit enhanced photoresponse with photocurrent density of 5.87 mA·cm−2, on/off current ratio of 3.01 × 104, and responsivity of 1.83 A·W−1 when a UV irradiation of 3.26 mW·cm−2 and 1.0 V bias were used. Theory analysis is also presented to get insight into the inherent mechanisms of separation and transportation of photo-excited carriers in RGO/ZNWs composite.

Enhancing the Photoelectric Performance of Photodetectors Based on Metal Oxide Semiconductors by Charge‐Carrier Engineering

“…Carbon materials such as graphene, graphdiyne, activated carbon and carbon nanotubes, are suitable candidates for composite film PDs owing to their superior optical and electric properties . Chen et al proposed the UV‐assisted photochemical reduction of GO in zinc oxide nanowires (ZNWs) suspension to achieve the formation of graphene sheets attached in ZNWs network and the enhancement of UV absorption . Compared with the PDs based on pure ZNWs, the optimized PD based on RGO/ZNWs composite exhibits an enhanced photoresponse with a photocurrent density of 5.87 mA cm −2 , an on/off current ratio of 3.01 × 10 4 , and a responsivity of 1.83 A W −1 under a UV irradiation (3.26 mW·cm −2 ) at 1.0 V. It is deduced that the extremely large interface area of graphene/ZNWs suppresses the carrier recombination and improves the carrier transport, thus leading to the photoresponse enhancement.…”

Solar-blind ultraviolet detection based on TiO2 nanoparticles decorated graphene field-effect transistors

“…Ultraviolet (UV) photodetectors are important for many applications such as space communication, flame detection, military surveillance, industrial quality control, and environmental monitoring [1][2][3][4][5][6][7][8][9][10]. Due to the excellent electrical and optical properties, such as ultrafast carrier mobility [11][12], high conductivity, ultra-wide spectral range (from UV to terahertz) [13][14][15] and tunable optical properties via electrostatic doping [16,17], graphene has attracted enormous attention as a promising candidate for high-performance photodetectors.…”

Low-Power Graphene/ZnO Schottky UV Photodiodes with Enhanced Lateral Schottky Barrier Homogeneity

“…Among various graphene-based hetero-architectures, the graphene/inorganic semiconductor contacts have attracted much attention because of their ample potential for high-performance Schottky photodiodes (PDs) [4]. For example, the enhanced photoresponse characteristics with high sensitivity and fast response were demonstrated on various graphene-based Schottky PDs that were composed of typical inorganic semiconductor materials (e.g., Si [5,6], Ge [7], GaAs [8,9], CdSe [10], ZnO [11,12,13,14,15,16,17,18,19,20,21], etc.). Among them, ZnO is one of the most prospective materials for high-performance ultraviolet (UV) PDs because of its wide band gap and excitonic properties [22,23].…”