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

摘要

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 J(sc),V-oc, and the conversion efficiency. Finally, we attained significant improvements of J(sc) = 39.06 mA/cm(2), V-OC = 647 mV, FF = 78.09, and conversion efficiency = 19.73% (C) 2014 Elsevier Ltd. All rights reserved.