The Effect Of Bond Concentrations On Solar Cell's Properties And Silicon Passivation

The silicon nitride (SiN_x:H) film deposited by plasma-enhanced chemical vapor deposition (PECVD) has been widely used in mass production of solar cells because of its good-antireflection and low-cost. In the research and investigation of high efficiency silicon solar cell, the passivation of front surface and anti-reflection has been their focus. Because, for the front surface, we need it have excellent passivation quality and good antireflection property, in this way to improve the short current and open voltage, then to get much higher efficiency.The optical properties, passivation effect of SiN_x:H deposited by PECVD and their correlation with bond concentrations had been studied. By varying the silane-to-total gas ratio, films with controlled refractive index (n) were deposited. According to the spectroscopic ellipsometry and Fourier transform infrared transmission spectroscopy (FTIR) testing results, the relationship between the N/Si atoms ratios and flow ratios was analyzed carefully, and the changes in Si-N, N-H, Si-H bonds concentration and the effect by annealing were discussed, too. The regularity for change of bond concentration was demonstrated in detail. We compared the change in lifetime average values and distribution before deposition, after deposition and after annealing after the tracking testing on lifetimes. Then the effect on film's property by the change in internal structure was analyzed carefully according to the results of bond concentrations. Finally, solar cells were made under different experiment processes, and the influences on their electric properties by films'qualities were discussed.