Novel cost-effective bifacial silicon solar cells with 19.4% front and 18.1% rear efficiency

Bifacial solar cells are a promising possibility to lower the costs of solar electricity compared to conventional monofacial solar cells. These devices utilize the sunlight more efficiently since they are able to convert Light incident on both sides of the cell. In this letter, a novel, cost-effective bifacial silicon solar cell structure is presented. On float-zone silicon, the cells exhibit conversion efficiencies of 19.4% and 16.5% under 1-sun front and rear illumination, respectively. Furthermore, a ''symmetrical'' version of the cells is presented demonstrating front and rear efficiencies of 18.4% and 18.1%. In spite of the simplicity of the cell fabrication process, these are the highest independently confirmed efficiencies ever reported for bifacial silicon solar cells. (C) 1997 American Institute of Physics.