Self-Powered Ultraviolet Photodetector Based on β-Ga2O3/WO3 NPs Heterojunction With Low Noise and High Visible Rejection

Self-powered ultraviolet (UV) photodetectors (PDs) have attracted numerous interests for high-performance and low power consumption, making wireless and independent operation possible. Herein, the solution processed tungsten oxide (WO 3 ) nanoparticles (NPs) were employed to construct \boldsymbol {\beta } -Ga 2 O 3 /WO 3 planar heterojunction PD. The formation of type-II \boldsymbol {\beta } -Ga 2 O 3 /WO 3 heterointerface generated typical photovoltaic effect enabling self-powered work manner. Importantly, the fabricated \boldsymbol {\beta } -Ga 2 O 3 /WO 3 NPs PD demonstrated record low noise with dark current of 6.5 fA and prominent spectral selectivity with rejection ratio ( {R}_{265} / {R}_{400} ) of 5.3\,\,\times10 4 , as well as excellent photodetection properties with photo-to-dark current ratio of 6.4\,\,\times10 5 , ON/OFF switching ratio of 2.7\,\,\times10 4 , responsivity of 4.1 mA/W, detectivity of 9.0\,\,\times10 12 Jones and rise/decay time of 168/171 ms at 0 V. Besides, the narrower bandgap and UVB spectral response of WO 3 NPs extended the detectable wavelength to 310 nm realizing broadband photodetection. The low-cost manufacture process and high self-powered performances pave the way of \boldsymbol {\beta } -Ga 2 O 3 /WO 3 NPs PD in next-generation nanodevices.