Multi-tip nano-prisms: Controlled growth and emission enhancement properties
1 National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing 210093, China
2 Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University - Nanjing 210093, China
Received: 28 June 2013
Accepted: 30 September 2013
We report here the experimental observations that the tip topography of ZnO nano-prisms sensitively depends on the percentage of oxygen in the flux of the carrying gas in vapor growth. At a relatively high oxygen concentration, a number of thin filaments can be nucleated atop nano-prisms, forming a unique fish-spear–like multi-tip morphology. The length and density of the “spear tines” depend on the flux of the carrying gas. The field emission properties of the nanorod array with different tip morphology are investigated. The structures with longer and denser spear tines possess lower turn-on electric field and higher electric current density. The cathodoluminescence properties of the ZnO nano-prisms have also been studied. The luminescence related to defects in multi-tip nano-prisms possesses the strongest intensity, and the nanorod without any tine structure possesses the lowest defect luminescence intensity. The intrinsic luminescence of ZnO around 385 nm, however, has the opposite tendency. We suggest that our observation is inspiring in optimizing the emission properties of the nanowire devices.
PACS: 81.10.Bk – Growth from vapor / 79.70.+q – Field emission, ionization, evaporation, and desorption / 85.35.-p – Nanoelectronic devices
© EPLA, 2013