XIS: A low-current, high-voltage back-junction back-contact photovoltaic device

In this paper we present a low-current, highvoltage back-junction back-contact integrated photovoltaic concept and experimental results of such a device, consisting of strip cells: narrow solar cells instead of conventional square cells. The concept is demonstrated by the successful transformation of a completely finished IBC cell into a XIS (Crystalline Silicon Interconnected Strips) device, leading to a V_oc of 8.5 V for a series connection of 14 strip cells. For cell separation, different grooving methods were evaluated with respect to their effect on the quality of the groove surface. The effect of the surface passivation in the grooves, which is regarded as a critical parameter, on the XIS device was simulated to gain a better understanding of the processing requirements.