Density of ZnO Nanotip Array Controlled by ZnO Seed Layer

Abstract

ZnO nanotips were synthesized on a sputtered ZnO buffer layer/ITO/glass by aqueous solution deposition with precursors of zinc nitrate and ammonia. The density of ZnO nanotips can be controlled by the thickness of sputtered ZnO buffer layer. The average height of 13 μm was obtained at 70°C for 24 hr and the diameter of ZnO nanotips was ranged from 60 nm to 100 nm. By thermal annealing at 300 oC in N2, the ZnO quality can be much improved and strong Micro-PL UV emission (380 nm) and lower defect emission (520 nm) of visible region are obtained. After thermal annealing at 300 °C in O2, both emissions are much improved.