Improved rear-side passivation by atomic layer deposition A ₂ O ₃ /SiN _x stack layers for high V _OC industrial p-type silicon solar cells

This research develops high open-circuit voltage (VOC)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° C) thermal atomic layer deposition of Al ₂ O ₃ layers and plasma-enhanced chemical vapor deposition of SiN _x 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.