Title :
Novel concept for thin multi-crystalline silicon solar cell process
Author :
De Wolf, S. ; Dekkers, H.F.W. ; Agostinelli, G. ; Szlufcik, J.
Author_Institution :
Dept. of Electr. Eng., Katholieke Univ., Leuven, Belgium
Abstract :
Solar cells on thin (/spl les/150 /spl mu/m) multi-crystalline Si (mc-Si) substrates require diffusion lengths exceeding twice the substrate-thickness combined with an excellent rear-surface passivation in order to reach efficiencies above 16%. Moreover, thin substrates no longer allow the use of screenprinted Al for back-surface-field (BSF) and contact formation, due to excessive warping upon firing. Gettering originating from POCl/sub 3/ emitter diffusion, is shown to enhance the bulk-quality to fulfill the first requirement. PECVD amorphous-Si (a-Si) layers, on the other hand, provide very low surface recombination rates. As a consequence, a POCl/sub 3/ diffused front emitter, combined with a heterostructure a-Si/mc-Si rearside is suggested to overcome the several constraints present when shifting to the use of thinner substrates within a low-cost environment.
Keywords :
amorphous semiconductors; carrier lifetime; diffusion; elemental semiconductors; getters; passivation; plasma CVD coatings; semiconductor thin films; silicon; solar cells; surface recombination; PECVD amorphous silicon layers; POCl/sub 3/ emitter diffusion; Si-Si; back surface field; chemical vapour deposition; contact formation; diffusion lengths; firing; gettering; heterostructure amorphous silicon-multicrystalline silicon; plasma enhanced CVD; rear-surface passivation; screenprinted aluminium; surface recombination; thin multicrystalline silicon solar cell process; warping;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Conference_Location :
Osaka, Japan
Print_ISBN :
4-9901816-0-3
