Passivating thin bifacial silicon solar cells for industrial production

A scheme for passivating thin multi-crystalline silicon solar cells compatible to mass production is presented. Wafers with a thickness of 180 mu m were processed into solar cells. The otherwise severe bowing has been avoided by reduced aluminium coverage on the rear surface. The process scheme includes a silicon nitride firing through step for conventional screen printed contacts, where a silicon nitride layer on the rear surface acts as surface passivation layer and enables a gain in efficiency of 0.6% [abs.].