Ultraviolet photodetector based on ZnO nanorods grown on a flexible PDMS substrate

A flexible, reproducible, sensitive and low-cost ultraviolet (UV) detector has been fabricated based on zinc oxide (ZnO) nanorods grown on a patterned polydimethylsiloxane (PDMS) substrate. The substrate was seeded with ZnO nanoparticles synthesised via simple low-temperature hydrothermal method using pomegranate peel extract as a reducing agent. The produced ZnO-nanorods/PDMS (ZnO-NR/PDMS) samples were tested for their UV-sensing properties. Samples were characterised using scanning electron microscopy, X-ray diffraction, I–V characteristics, UV-Vis spectroscopy and photoluminescence measurements. The UV photoresponse mechanism of prototype UV detector was analysed. The detector exhibited quite high on/off ratios between photoresponse current and dark current. With the flexible PDMS substrate, the detector photoresponse was tested with and without bending and exhibited a very slight change in the photoresponse current. The detector current–time response was also tested under various UV light intensities for three test cycles to examine the detector stability, hysteresis behaviour and performance. It is anticipated that the fabrication of ZnO-NR/PDMS UV detector may have significant potential application in flexible optoelectronic devices.