Growth of ZnO nanorods via metalorganic chemical vapor deposition and their electrical properties

Growth behaviors of ZnO nanorods synthesized by catalyst-free metalorganic chemical vapor deposition were studied as functions of various growth parameters such as growth temperature, precursor ratio and substrate type. We found that their sizes, shapes and alignment nature were strongly dependent on such parameters. However, individual ZnO nanorods were of single-crystalline nature as well as of high optical quality. Field effect transistors (FETs) using single ZnO nanorods were fabricated to study their electrical properties. Ultraviolet illumination and vacuum environment resulted in a significant increase of mobile electrons. Investigation on temperature-dependent electrical transport revealed that thermionic emission dominated as a current transport mechanism in the FETs.