Surface textured ZnO films for thin film solar cell applications by expanding thermal plasma CVD

Abstract

An expanding thermal plasma created by a cascaded arc is used to deposit surface textured ZnO films. Films have been deposited at 150–350°C at a rate of typically 0.70 nm/s. They exhibit low resistivity (<10 −3 Ωcm), high transmittance in the visible wavelength region (>80%) and a rough surface texture. The crystallite size and surface roughness increase with increasing deposition temperature and flow of argon ions. At the same time columnar textured growth gets less pronounced, a change to granular growth is observed. First p-i-n a-Si:H solar cells deposited on this material with initial efficiencies approaching 10% have been realised.