Ultra-Wide Bandgap Copper Oxide: High Performance Solar-Blind Photo-detection

High-performance solar-blind photo-detection using highly transparent CuO nanostructures (with a bandgap of 4.15 eV) has been demonstrated. The device shows the dark current as low as 0.2 nA (-10 V applied bias) and no signature of breakdown even at a bias up to ±175 V. The device has shown record photo-sensitivity of 610, photo-responsivity of 14.02 A/W and photo-detectivity of 3.59 × 10
¹³
cmHz
^1/2
W
^-1
in the UV-C region. The ratio of photo-responsivities at 210 nm and 500 nm i.e. R
₂₁₀
/R
₅₀₀
was found to be 5.05 × 10
⁴
. Additionally, the device has shown external quantum efficiency of ~5900 % at 210 nm excitation. This letter will establish CuO as one of the most promising ultra-wide bandgap semiconductors for costeffective solar blind photo-detection.