Transparent and conducting boron doped ZnO thin films grown by aerosol assisted chemical vapor deposition

Abstract

ZnO based transparent conducting oxides are important as they provide an alternative to the more expensive Sn : In₂O₃ that currently dominates the industry. Here, we investigate B-doped ZnO thin films grown via aerosol assisted chemical vapour deposition. B : ZnO films were produced from zinc acetate and triethylborane using either tetrahydrofuran or methanol (MeOH) as the solvent. The lowest resistivity of 5.1 × 10⁻³ Ω cm along with a visible light transmittance of ∼75–80% was achieved when using MeOH as the solvent. XRD analysis only detected the wurtzite phase of ZnO suggesting successful solid solution formation with B³⁺ substituting Zn²⁺ sites in the lattice. Refinement of the XRD patterns showed minimal distortion to the ZnO unit cell upon doping when MeOH was the solvent due to the immiscibility of the [BEt₃] solution (1.0 M solution in hexane) in methanol that limited the amount of B going into the films, thus preventing excessive doping.