Structural, optical and electrical properties of natively textured ZnO grown by PECVD for thin-film solar cell applications

Natively textured ZnO layers have been deposited between 150 and 350 °C with an expanding thennal plasma created by a cascaded arc. As shown by Scanning Electron Microscopy, Atomic Force Microscopy, X-ray Diffraction, and optical measurements, the crystallite size and surface roughness of the films increase with increasing substrate temperature. At the same time, columnar textured growth becomes less pronounced, and a change to granular structure is observed.The ZnO films exhibit low sheet resistance (<10 ..QIc~), high transmittance in the visible wavelength region (>80%) and effective light scattering properties. Preliminary amorphous silicon pin solar cells deposited on ZnO show an initial efficiency approaching 10 %, close to the value obtained on Asahi U-type Sn02:F.