Investigation of growth parameters influence on Au-catalyzed ITO nanowires by electron beam evaporation method

Abstract

Indium tin oxide (ITO) nanowires (NWs) were synthesized via Gold (Au) catalyst assisted Vapor–Liquid–Solid (VLS) growth mechanism by electron beam evaporation method (EBE). Effects of growth parameters such as evaporation rate of ITO, oxygen partial pressure, and different types of substrates on the growth of ITO NWs were studied. Experimental investigations show that the Au-catalyzed VLS growth mechanism was dominating over self-catalytic VLS growth mechanism at lower evaporation rates of ITO. Self-catalytic VLS growth was dominating over Au-catalyzed VLS growth at the higher ITO evaporation rates of 6 Å/sec and above. Furthermore, change of growth mechanism was explained by considering incubation time and diameter of the catalyst particles. It was observed that the NWs growth enhanced at lower oxygen partial pressures and completely seized at higher oxygen partial pressure of 6×10−4 mbar and above. The complete absence of NWs growth at higher oxygen partial was explained by considering the growth rates of VLS and VS deposition. It was found that, the ITO NWs growth is independent of type of the substrate used. Understanding the growth mechanism transition and growth behaviour with deposition parameters are novel findings for the present report. In addition to the above, optical and electrical properties of ITO NW films were also studied. These ITO NWs films will be useful in antireflection, transparent conducting oxide coating applications. Moreover, these ITO NWs films may improve the performance of the various optoelectronic devices.