ZnO Microtetrapods Covered by Au Nanodots as a Platform for the Preparation of Complex Micro-nano-structures

Abstract

We propose to use hybrid networks of ZnO microtetrapods produced by flame transport synthesis and Au nanodots deposited by pulsed electroplating, for the preparation of more complex 3D micro-nano-structures via Au catalyst-assisted vapor-liquid-solid growth of semiconductor nanowires on the surface of ZnO microtetrapod arms. The pulsed electrochemical deposition of Au nanodots with optimized pulse parameters was realized in pressed pellets containing the ZnO tetrapods with the density 1 g cm−3. The mechanical stability was increased by means of thermal treatment of pressed hybrid networks of ZnO microtetrapods at 950 ℃ for 1 h. The morphology of the ZnO microtetrapod networks and the density of the deposited Au nanodots were investigated by scanning electron microscopy. The deposition of Au nanodots with various densities and of monolayers of self-assembled nanodots was demonstrated on ZnO microtetrapods possessing different conductivities. The optical quality of the ZnO microtetrapods was investigated by photoluminescence (PL) spectroscopy in the temperature interval from 10 to 300 K. PL bands related to neutral donor bound excitons D0X and donor–acceptor pairs (DAP) recombination were observed at low temperature. We assume that the presence in the spectrum of PL bands related to excitonic radiation is indicative of a high enough quality of the investigated ZnO microtetrapods for various optoelectronic and photonic applications.