Theoretical analysis of textured thin-film solar cells and a guideline to achieving higher efficiency

A total-area conversion efficiency of 12.0% has been achieved for a 100 cm/sup 2/ single-junction a-Si solar cell, by the use of a high-quality i-layer and other successful techniques such as a high-quality buffer layer treated by hydrogen plasma. For further improvement, the first exact numerical model has been proposed for submicron "textured" a-Si solar cells. Some important results have been obtained with the model. For example, the nonuniformity of the electric field in the textured structure was quantitatively analyzed. For a cell with a structure of glass/TCO/a-Si/metal, the incident light is trapped inside the cell, similar to that in fiber optics, mainly due to the small loss of light escaping from the a-Si to the glass.< >