Advanced dry processes for crystalline silicon solar cells

Significant cost reduction of bulk crystalline silicon solar cells requires the removal of the technological barriers that impede the development of a high throughput, low cost, and reliable industrial process on thin substrates. Present industrial surface conditioning and rear surface passivation processes do not meet the requirements for yield and performance on thin substrates. In addition, large-scale production brings about the issue of the environmental impact of PV processing and its related externalities, which may contribute a significant part of the final costs and are so far, underestimated or belittled. In this paper we present an advanced, plasma-based processing technology, suitable for industrial production of bulk silicon solar cells on thin substrates and capable of meeting the PV market growth challenge with a low environmental impact and a competitive cost. The modified processing steps include plasma etching and texturing, dielectric passivation and rear side local contact schemes. Each step is compatible with the standard process sequence, can be integrated separately in the production line and leads to improved performance and/or cost reduction.