α/β phase junction Ga2O3 based high-performance self-powered deep ultraviolet photodetectors with Ti3C2/Ag nanowire hybrid conductive electrode

Abstract

Gallium oxide (Ga2O3) semiconductor has attracted increasingly interested in the optoelectronic field, due to the wide bandgap of 4.9 eV. However, the fabrication of Ga2O3 pn junction is still an enormous challenge since p-Ga2O3 doping technology is in its infancy. Taking into consideration the α-Ga2O3 and β-Ga2O3 with comparable band gap structure, a solar-blind photodetector was constructed by the vertical α/β-Ga2O3 junction nanorod arrays (NRAs) with a top electrode for a Ti3C2-silver nanowires (Ag NWs). Compared to a standard metal electrode, the Ti3C2-Ag NWs electrode with tight coupling of the α/β-Ga2O3 demonstrated outstanding conductivity and optical transparency, optimizing the photodetector with excellent photoelectric performance. Meanwhile, the photogenerated carriers were easier to automatically separate and transfer to their corresponding electrodes because of the internal electric field of the α/β-Ga2O3 phase junction could drive the photogenerated charge transfer, promoting the photogenerated electrons transfer. Even without external power, the photodetector demonstrated improved performance, large detectivity of 1.45 × 1014 Jones, and high responsivity of 5.2 mA/W. The solar-blind photodetector with self-powered shows high photoelectric performance, which has prospective applications in space missile detection, UV communication, and deep ultraviolet light monitoring.