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

Abstract

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× 1013 cmHz 1/2W-1 in the UV-C region. The ratio of photo-responsivities at 210 nm and 500 nm i.e. R210/R500 was found to be 5.05× 104. 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 cost-effective solar blind photo-detection. © 1980-2012 IEEE.