A crossbar-type high sensitivity ultraviolet photodetector array based on a one hole–onenanorod configuration via nanoimprint lithography

Abstract

Single crystalline vertical ZnO nanorods were grown in a one hole–one rod configuration usinga hydrothermal method with a patterned polymer template generated by nanoimprintlithography, allowing precise control over the position and density of the ZnO nanorods. An 8 × 8 ZnO nanorod-based ultraviolet photodetector array is demonstrated, inwhich a well-confined number of ZnO nanorods are sandwiched betweencrossbar-type platinum and indium tin oxide electrodes (e.g. 16 nanorods in a2 × 2 µm2 area). A high photocurrent/dark current ratio of3 × 103 at a reverse bias of 1.5 V under UV illumination at room temperature, a responsivity of 4381.4 A W − 1 at 365 nm, and an ultraviolet-to-visible rejection ratio of 83 are obtained and maintained,irrespective of pixel size. A uniform photoresponse is achieved in each of the pixels,indicating the scalability with this technique for fabricating an integrated UVphotodetector array circuit.