Influence of the Transition Region Between n- and p-Doped Silicon on IBC Solar Cells

In this work, we review the influence of the transition region between n- and p-doped silicon on IBC solar cells, focussing on the "back-contact back-junction" architecture. In the first iterations of these IBC solar cells, an undoped "gap" between n- and p-doped regions was implemented. Alternatively, a buried emitter, floating base or gapless structures are possible. Such cells have been experimentally realized and their performance has been analyzed and investigated by additional simulation. Learnings have been transferred to TOPCon IBC solar cells. Gapless structures offer a very lean process flow, while maintaining a high performance for classical IBC solar cells. TOPCon IBC solar cells require a sufficient gap or trench to prevent dominating lateral recombination from the transition region. Both can be modelled by approaches reviewed in this work.