Investigations on low-cost back-contact silicon solar cells

Back-contacted cells offer multiple advantages in regard of reducing module assembling costs and avoiding grid shadowing losses. The investigated emit ter-wrap-through (EWT) design is equipped with a front and a rear emitter ( Gee et al., Proceedings of the 23th IEEE PVSC, 1993, p. 265). Both emitter areas are electrically connected by small holes drilled into the crystallin e silicon wafer. Renouncing on expensive photolithographic steps several te chniques appropriate for a low-cost process have been investigated. An incr ease in J(sc) of 15% was measured when compared to a conventionally process ed reference cell. However, the open-circuit voltage V-oc and the fill fact or did not improve. Possible reasons for these losses are presented in this paper. The efficiency of one of the best low-cost EWT cells within this wo rk reached 13.6% on Ct-silicon, which is the highest efficiency reported so far for this cell type (Schonecker et al., Proceedings of the Second WCPSE C, 1998, p. 1677). (C) 2001 Elsevier Science B.V. All rights reserved.