The influence of silicon nitride layer parameters on the implied Voc of CZ silicon wafers after annealing

The passivation potential of PECVD SiN_x deposited on undiffused p-type Si surfaces is investigated. The influence of post-deposition annealing temperature and the film parameters (refractive index and thickness) on the implied Voc of textured, commercial grade, p-type CZ wafers was studied. Improvement in the implied Voc values of SiN_x passivated CZ wafers was observed for two different SiN_x films for all annealing temperatures in the range of 600-820°C. Excellent implied VOC values above 700 mV achieved on these wafers indicate that this process can be potentially used as rear passivation for various commercial cell technologies. Initial results on the use of this process in the fabrication of the new Double Sided Laser Doped solar cells structure demonstrate this potential.