Thomas Pass

Generation III high efficiency lower cost technology: Transition to full scale manufacturing

This paper reports on the first large scale manufacturing of Gen III solar cells. The Gen III product has been designed to deliver increased performance and lower cost throughout the value chain. Reduced emitter recombination is the key feature to deliver the efficiency improvement. Gen III is now ramping on a production line in SunPowers Philippines manufacturing plant. Production run median efficiency is 23.6%. Total area module efficiency is 21.2 %. The Gen III solar cell architecture has a low breakdown voltage in reverse, which minimizes power loss and wear on module materials under shaded conditions.

Degradation of surface quality due to anti-reflective coating deposition on silicon solar cells

We find that the front surface quality on back contacted silicon solar cells is degraded by the evaporative deposition of an anti-reflective coating. The degradation is most severe when an e-beam evaporation is performed, but there is still significant degradation with thermal evaporation. The surface recovers some after a forming gas anneal but is still degraded compared to before the evaporation. The degradation overwhelms and negates any forming gas anneal performed prior to the evaporation. The degradation is greatly reduced if the surface is not textured. We discuss the application of these results to our high efficiency silicon solar cells.