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.