Effect of back opening ratio and layout design on the performance of laser ablated point contact cell

Abstract

In this paper we investigate the effect of the opening ratio and the back layout design on the electrical performance of the solar cell. First, the point contact solar cells are optimized by adjusting the laser opening ratio and the virtual-to-real ratio on each grid line of back side. The experimental results show that the open-circuit voltage (Voc) of the solar cell increases as the opening ratio decreases. Analysis of the PL images also shows that the damage to the passivation layer causes the Voc to drop. By characterizing the resistance of the back line, we found that laser drilling can cause an increase in the resistance of the back line. This can also lead to the FF loss. Then, by reducing the contact area of the bus-bar at the backside, the carrier recombination of the solar cell is reduced and the Voc of the cell is increased, resulting in a 0.07% increase in cell efficiency. Finally, the simulation shows that the openings lead to an increase in the recombination current (J01) at the base of the cell, which affects the efficiency of the cell.