Assisted passivation by a chemically grown SiO2 layer for p-type selective emitter-passivated emitter and rear cells

The performance of industrial-sized selective-emitter passivated emitter and rear cells (PERCs) is improved using different assisted passivation schemes using a method of nitric acid oxidation of silicon (NAOS) to form SiO2 layer. The measured internal quantum efficiency of short-wavelength photons confirms that the increase in short-circuit current density for front-emitter passivation PERCs by SiO2 is due to the improved response in the blue region associated with a decrease in the Auger recombination rate at the front surface. Gains in open-circuit voltage are attributed to the high level of chemical passivation induced by SiO2 in the n+-emitter, wherein the Shockley-Read-Hall and the Auger recombination are both low.207