A 20% efficient Sliver solar cell

Sliver® cells are thin, single-crystal silicon solar cells fabricated using standard fabrication technology. Sliver® modules, composed of several thousand individual Sliver® cells, can be efficient, low cost, bifacial, transparent, flexible, shadow-tolerant and lightweight. There are two distinct challenges related to Sliver® technology: providing a mature and robust Sliver® cell fabrication method that can produce a high yield of high efficiency Sliver® cells, and which is suitable for transfer to industry; and, handling, electrically interconnecting and encapsulating billions of SLIVER cells at low cost. This paper deals chiefly with the cell fabrication method, while a companion paper demonstrates that Sliver® cells can be extracted from the host wafer and encapsulated at low cost and low complexity. We have recently fabricated SLIVER cells with efficiencies exceeding 20% using the optimised processing sequence that is described in detail in this paper. This is believed to be the first commercial thin-film type technology to reach 20% efficiency. We believe that there is a path to laboratory cell efficiencies of 22% and commercially produced cell efficiencies of 21%.