ZnO is a wide bandgap semiconductor having a direct bandgap of 3.32 eV at room temperature. It has an exciton binding energy of 60 meV. It is found to be significantly more radiation hard than Si, GaAs, and GaN, which is critical against wearing out during field emission. Furthermore, ZnO can also be made as transparent and highly conductive, or piezoelectric. The ZnO nanotips can be grown at relatively low temperatures, giving ZnO a unique advantage over other wide bandgap semiconductors, such as GaN and SiC. In the present work, we report the selective growth of ZnO nanotips on various substrates using MOCVD. The ZnO nanotips are single crystalline, n-type conductive and show good optical properties. These nanotips have potential applications in field emission devices and UV photonics.
S. Muthukumar, H. Sheng, Z. Zhang
Proceedings of the 2nd IEEE Conference on Nanotechnology