Three-dimensional ZnO nanorods growth on ZnO nanorods seed layer for high responsivity UV photodetector

Three-dimensional ZnO nanorods (NRs) were synthesized by hydrothermal method on ZnO seed layer including horizontal ZnO NRs. The ZnO seed layers consist of different values of NRs were synthesized by spin-coating. The different seed layers and ZnO nanorods arrays were characterized using field emission scanning electron microscopy, X-ray diffraction. Horizontally dispersed NRs on the substrate formed an overlapping junction structure into seed layer as ZnO NRs network. NRs grown on the seed layer including horizontal NRs were oriented in different directions to form three-dimensional ZnO NRs in flower shape. The electrical resistance of sensors based NRs array decreased dramatically with increasing NRs added to ZnO seed layer. Results show that ultraviolet photocurrent increased from 1.7 to 23 mu A which is suitable for fabrication of practical photodevices.