Ordered Growth and Photoluminescence of ZnO Nano-Arrays on Silicon Substrates with Seed Film by Hydrothermal Method

Abstract

ZnO nano-arrays were successfully prepared on silicon substrates with seed film by hydrothermal inversion growth method. The seed films prepared by magnetron sputtering are generally suitable for the preparation of perfect ZnO nano-array films. The effect of solution concentration, reaction time and hydrothermal temperature on the morphology were analyzed systematically. For the ZnO nano-arrays prepared at the same temperature, the arrays cultivated in low-concentration growth solution were arranged neatly, the morphology was regular and the cross sections were hexagonal. With the concentration increasing, the nano-rods got longer and their tops became thinner. Prolonging the hydrothermal aging time helps optimize the morphology of the nano-arrays, which is very important for subsequent device preparation. Increasing hydrothermal temperature can shorten the aging time and effectively resist the environmental difference in different directions of the nano-rods, which can promote the disappearance of the upper tips and the formation of perfect nano-rod arrays. All the phenomena are determined by the growth mechanism of the ZnO nano-array. The growth mechanism was deduced in this paper according to the growing patterns reflected in experiments. The UV light emission of ZnO nano-array at 370 nm shows a certain regularity and the regularity is related to the change of morphology with solution concentration and hydrothermal temperature. This is very important for developing the application in optoelectronic devices.