Laser ablation of aluminum oxide and silicon nitride rear-side passivation for i-PERC cell

• i-PERC cells are one of the next-generation concepts for industrial mass production lines.
• We fabricated the PERC solar cells by using a commercial grade p-type wafer.
• DRE process using a diluted alkaline solution is possible to reduce laser damage.
• The test samples demonstrate the best opening line width and the rate of contact opening.
• In i-PERC cell, Jsc = 39.06 mA/cm2, Voc = 647 mV, FF = 78.09, and i = 19.73%.

Rear-side passivated solar cells are one of the next-generation concepts for industrial mass production lines. Our production line has achieved greater than 19% for a commercial-grade with a homogeneous POCl3 emitter. In this study we investigated an industrial passivated emitter and rear cell (PERC) structure with optimized laser ablation after the deposition of rear-side passivation layers of aluminum oxide and silicon nitride. Microscopy was carried out to compare the quality of the rear-side contact, opening, and local back surface field area. The rear-side pattern design of the line width and spacing was studied to improve the cell performance. Minimization of the series resistance is influenced by the contact area and line spacing. We have processed an i-PERC cell for evaluating the cell parameters. The optimized rear line contact scheme and screen-printing conditions made it possible to realize an increase Jsc, Voc, and the conversion efficiency. Finally, we attained significant improvements of Jsc = 39.06 mA/cm2, Voc = 647 mV, FF = 78.09, and conversion efficiency = 19.73%