Comparison of the Open Circuit Voltage for Point Contact and Linear Contact IBC Solar Cells

In order to show the effect of reducing the size of diffused regions for lowering their saturation current, two kinds of Interdigitated Back Contact (IBC) silicon solar cells have been manufactured: Linear Contact (LC) cell, and Point Contact (PC) cell. Isc — Voc measurements allow to determinate the saturation currents under different working conditions. It is shown that LC cell present better VQC than PC cell under low illumination levels (<500 kW/m2 AM 1.5) but under higher levels, the effect of emitters size reducing leads to an increased Voc. However, the Fill Factor and the efficiency can be limited by the simultaneous increase of the cell intrinsic series resistance. Efficiencies over 24% have been obtained under 300 kW/m2 with LC cells.