Improved Rear-Side Passivation by Atomic Layer Deposition Al2O3/SiNx Stack Layers for High VOC Industrial p-Type Silicon Solar Cells

This research develops high open-circuit voltage (V-OC) p-type industrial screen-printed silicon solar cells using improved rear surface passivation. It shows a significant improvement in the minority carrier lifetime by low temperature (<450 degrees C) thermal atomic layer deposition of Al2O3 layers and plasma-enhanced chemical vapor deposition of SiNx passivation layers. An increase in the V-OC and the short-circuit current (J(SC)) due to an improved long-wavelength response are also demonstrated. With the optimized stack layers, a high efficiency of 19.2% across a large area (156 cm(2)) is seen. Furthermore, the rear-side passivation scheme can be easily integrated into the conventional screen-printed process. This is very promising for in-line solar cell manufacturing.