UV–vis–IR Broad Spectral Photodetectors Based on VO₂–ZnO Nanocrystal Films

Abstract

As a narrow band semiconductor at room temperature and a metallic material above ∼68 °C, functional VO2 films are widely investigated for smart windows, whereas their potential for ultraviolet–visible–infrared (UV–vis–IR) broad spectral photodetectors has not been efficiently studied. In this report, photodetectors based on VO2–ZnO nanocrystal composite films were prepared by nanocrystal-mist (NC-mist) deposition. An enhanced photodetection switching ratio was achieved covering the ultraviolet to infrared wavelength. Due to the synergetic effect of nanosize, surface, phase transition, percolation threshold, and the band structure of the heterojunction, the transfer and transport of photogenerated carriers modulate the device performance. This study probes new chances of applying VO2-semiconductor-based nanocomposites for broad spectral photodetectors.

Nanoelectronics Using Metal–Insulator Transition

“…[33,190,191] Photoinduced MIT in Mott insulators can offer intriguing routes to overcome the limits of conventional optoelectronics, given their ability to exhibit the essential features for next-generation optoelectronics, including ultrafast switching, high on/off ratio, and low power consumption. However, as photogenerated carriers in Mott insulators themselves are insufficient to trigger the MIT by light, various methods have been proposed, such as heterojunction with functional materials, [192,193] nanostructure control, [194,195] and octahedral rotation and tilting, [196] facilitating photo-induced MIT in optoelectronic device applications.…”