Bandgap Engineering, Inc. announced on July 31st, 2013, that its proprietary and patented nanotextured silicon solar cells demonstrated a 0.3% absolute efficiency boost over industry-standard solar cells. The Bandgap nanotextured, 156 mm multicrystalline silicon cells, made in collaboration with Georgia Institute of Technology, achieved average efficiencies of 16.7%, as compared to industry-standard control cells that averaged 16.4%. Importantly, all the cells were processed using conventional processes including a standard emitter, silicon-nitride, screen-printed metallization with an aluminum back surface field.
“This efficiency boost is particularly impressive given that we have just begun to tune the cell process for our nanotextured silicon solar-cells,” stated Marcie Black, CTO of Bandgap. “When fully optimized we expect our cells will have an efficiency approximately 1% absolute higher than standard multicrystalline cells.”
“These results validate our strategy to upgrade existing crystalline silicon production lines with a low-cost, drop-in improvement,” commented Richard Chleboski, CEO of Bandgap. “We are ready to work with manufacturers interested in upgrading their production lines to sell a premium, differentiated products at lower costs per watt. In short, when fully implemented, our partners will be able to obtain monocrystalline cell performance and pricing with multicrystalline wafers and costs.”
Bandgap’s nanotextured solar cells are a drop-in upgrade for today’s crystalline silicon manufacturers using standard processing technologies. As the technology gives low reflection for all grain orientations, it is an ideal upgrade for multicrystalline wafers, which have higher reflection. Additionally it can enable several high efficiency and lower cost processes which are already on many manufacturers roadmaps. Specifically the single sided texture enables processes that require planer back surfaces for improved reflection or passivation. The low silicon consumption, less than 1 um is consumed in the texturing process, is ideal for thin silicon technologies. Also, Bandgap has developed approaches to pattern its silicon nanowires that can enable plated front metal contacts without laser patterning or lithography.
