Facile bottom-up growth of pyramidally textured ZnO:Al films by combined chemical bathing and DC sputtering deposition

Abstract

We developed a facile bottom-up approach to achieve the well-faceted pyramidally textured ZnO:Al (AZO) thin films on non-conductive glass substrates by combining chemical bathing and DC magnetron sputtering deposition. The chemical bathing deposition (CBD) was adopted to generate the ZnO nanorods (NRs) with a terminated plane of (001), followed by the further growth of (101)-faceted AZO pyramidal tips using DC sputtering. The structural, optical, and electrical properties of pyramidally textured AZO films were mainly governed by the size and distribution of ZnO NRs. When the length and the diameter of ZnO NRs were around 450 and 150 nm, respectively, controlled through the CBD process, the AZO film grown on the NRs showed a low resistivity of 9.7 × 10⁻⁴ Ω cm and a high average transmittance of 85.7 % at wavelengths of 400–1100 nm. The well-faceted pyramidal textures brought about a maximum haze value of 66.0 % at 355 nm and an average haze of 14.5 % at wavelengths of 355–1100 nm. This proposed simple strategy may benefit the studies on growth of pyramidally textured transparent conducting oxides on non-conductive substrates for high-efficient light harvesting through a low-cost and scalable process.