High-quality passivated rear contact structure for silicon solar cells based on simple mechanical abrasion

Recently, a novel easy-to-fabricate passivated rear contact structure has been developed at ISFH. Simple mechanical abrasion is applied to form line-shaped contact openings in a previously deposited surface-passivating dielectric layer. This simple approach avoids any photolithographical processing and back surface field formation. The influence of mechanically induced crystal defects is discussed. Comparison of cell results to photolithographically defined point contact schemes shows equally high solar cell performance. By applying the novel rear surface structure efficiencies of 21% and 20% have been achieved for laboratory size 4 cm(2) and industrial size 10 x 10 cm(2) solar cells, respectively.