ZnO based Back Reflectors with a Wide Range of Surface Morphologies for Light Trapping in n-i-p Microcrystalline Silicon Solar Cells

Surface morphology of ZnO layers with as-deposited thickness between 550 to 1050 nm was varied over wide range by changing etching time. The surface morphology of these ZnO layers was measured by atomic force microscopy (AFM) and statistically analyzed in terms of root mean square roughness and the diameter and depth of the craters. The texture-etched ZnO covered with a Ag and ZnO layers were applied into n-i-p μc-Si:H solar cells as back reflectors. The effects of the back reflector morphologies on solar cell performances were investigated. The link between the morphology, the scattering properties of ZnO layers, and the solar cell performance is discussed.