Self-textured ZnO via AACVD of alkyl alkoxides: a solution-based seed-less route towards optoelectronic-grade coatings

Abstract

ZnO thin film coatings were synthesised by aerosol-assisted chemical vapour deposition (AACVD) from molecular precursors with different Zn : O ratios, from which synthetic parameters that promote self-texturing were analysed. To that end, the effect of the Zn environment and temperature on the morphology of the resulting ZnO coatings was evaluated for a wide range of synthetic conditions. With the aim to overcome the issues of commercial ZnO precursors, a non-pyrophoric molecular precursor has been investigated to produce 002-oriented, compact, transparent ZnO thin coatings with minimal carbon contamination at 300 °C and fast growth rates (>40 nm min⁻¹). The deposition described herein is a new approach to rapidly achieve coatings at ambient pressure with optimal conditions for optoelectronic applications, and their potential as structural templates to epitaxially grow ZnO in a fast tandem configuration. The results presented in this work provide important insight on the influence of the chemical precursor properties and synthesis conditions to deliver functional ZnO coatings via solution-based methods, while obtaining morphologies only achievable by physical vapour deposition techniques.