Single furnace-step processed large area mc-Si solar cells

Cost-effectiveness of silicon solar cell production can be improved by using cheaper materials and by simplifying the manufacturing process. In a typical low-cost process for multicrystalline silicon solar cells there are two or three thermal processing steps. We have developed a process that combines emitter formation and aluminum back contact formation in a single furnace process step. The process provides phosphorus and aluminum gettering and hydrogen passivation. The aluminum diffusion on the rear surface introduces an effective back surface field. Gettering efficiency and effect of back surface field have been analyzed using μPCD lifetime measurements. A PECVD-grown SiN_x film is used as an antireflection coating and for front surface passivation. Chromium-copper front contacts are formed using a simple self-aligning photolithography process and lift-off