Solution-Processed Transparent CuO Thin Films for Solar-Blind Photodetection

Abstract

Highly transparent (Transmittance >90%), solution-processed thin films of CuO with a direct bandgap of 3.87 eV were first time utilized for solar blind photo-detection. The CuO thin-film-based photodetector has shown very large DUV/Vis. rejection ratio of ~5430. The device has shown photo-responsivity value of 7.77 AW<inline-formula> <tex-math notation= LaTeX >$^{-\\textsf {1}}$ </tex-math></inline-formula> and photo-detectivity of <inline-formula> <tex-math notation= LaTeX >$3.08\\times 10^{\\textsf {11}}$ </tex-math></inline-formula> cm<inline-formula> <tex-math notation= LaTeX >$\\cdot $ </tex-math></inline-formula>Hz<inline-formula> <tex-math notation= LaTeX >$^{\\textsf {1/2}}\\cdot \\text{W}^{-\\textsf {1}}$ </tex-math></inline-formula>. Interestingly, the device has shown persistent photoconductivity with a retention time of several days. In order to use the device for optical memory, the reset mechanism has been successfully demonstrated by annealing the device at 50 °C. The developed solution processed, highly transparent, solar-blind photodetector has immense potential for next-generation cost-effective optoelectronic devices.