PECVD Silicon Nitride Surface Passivation for High-Efficiency N-Type Silicon Solar Cells

In this paper, we show that plasma-enhanced chemical vapor deposited silicon nitride is particularly well suited for surface passivation of n-type silicon wafers and solar cells. The surface passivation quality provided by the silicon nitride on three different important surfaces for high-efficiency n-type solar cells is studied in this work: planar, textured, and boron-diffused surfaces. Exceptional passivation quality on these surfaces is demonstrated in this work. One-sun implied open-circuit voltages of 732 mV, 719 mV, and 683 mV were achieved on 1 ohm.cm planar, 1 ohm.cm textured, and moderately doped (135 ohm/sq) boron-diffused planar surfaces, respectively. A real open-circuit voltage of 719 mV was measured at approximately 1-Sun, 25 degC condition on a voltage test structure device passivated entirely with silicon nitride