Control growth of catalyst-free ZnO tetrapods on glass substrate by thermal evaporation method

Novel three-step directions of glass substrate for catalyst-free growth of ZnO tetrapods (ZnO-Ts) without using catalyst or seed layer via thermal evaporation method were investigated. In this study, controlled synthesis of ZnO-Ts was achieved through glancing angle deposition by three-step directions of glass substrate with inclination angles of 0 degrees, 45 degrees, and 90 degrees toward the gas flow at a growth temperature of 650 degrees C. The effects of substrate inclination angles on the morphological, structural, and optical properties were systematically investigated using field emission scanning electron microscopy, X-ray diffraction, UV vis spectroscopy, and photoluminescence spectrum. Results showed that the substrate tilt angle is one of the most critical control parameters in determining the nucleation and growth of ZnO-Ts. This new approach provides a cost-effective and simple method for the synthesis of tetrapods, which can be useful in various optoelectronic applications and solid-state devices. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.