Self-assembly of aligned CuO nanorod arrays using nanoporous anodic alumina template by electrodeposition on Si substrate for IR photodetectors

Hexagonally highly-ordered thin nanoporous anodic alumina (AAO) template of pre-deposited Al thin film onto Si substrate was fabricated under controllable conditions through a two-step anodization for the growth of nanostructured materials. The obtained AAO template has approximately 60 nm of pore diameter and 1200 nm length with 110 nm interpore distances within an area of 0.75 cm2. A bottom barrier layer of the AAO template was removed by wet etching using phosphoric acid (5 wt%) for several minutes at room temperature. As an application, Cu nanorod-arrays embedded in AAO template was prepared by dc electrodeposition. The electrodeposited Cu nanorod-arrays onto Si based AAO template were oxidized at optimized conditions inside a conventional furnace to produce high-quality CuO nanorod arrays. The free-standing CuO nanorod arrays were formed after subsequent removal of AAO template. Fast with high-performance CuO nanorod-arrays IR photodetector based on MSM were fabricated with Al contact electrodes and its optoelectronic properties were examined. The electrical performance and photoelectric response performance were studied and the results showed that IR photodetector exhibited a high sensitivity to 808 nm IR laser light. Both the response and recovery time were found to be fast; 0.19 and 0.17 s, respectively, which are much shortest time compared to other IR photodetectors reported in the literature.