Rear side passivation characteristics of silicon oxy nitride films for high efficiency silicon solar cell

摘要

High quality rear surface passivation is a prerequisite to obtain high conversion efficiency on thin wafers. SiOxNy with low absorbance and variable refractive index inherits the properties of both SiNx and SiO2 which act as a rear surface reflector. SiOxNy layer with low refractive indices ranging from 1.51 to 1.61 was deposited and their chemical composition was analyzed by Fourier transform infrared (FTIR) spectroscopy. With the optimized SiOxNy layer the I-V results yielded a short circuit current density (Jsc) of 38.7 mA/cm2 and efficiency of 19.34%, with open circuit voltage (Voc) of 635 mV.