Characterization and application of a-SiCx:H films for the passivation of the c-Si surface
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In this work we investigate the effects of typical thermal treatments on c-Si surface passivation by intrinsic a-SiCx:H films. First, a forming gas anneal (FGA), (400 °C, 30 min in H2/N2) is applied resulting in an improvement in surface passivation. The best result is a surface recombination velocity lower than 23 cm s-1. A second thermal step (730 °C, 30 s) is studied to try and simulate the firing step for screen-printed contacts. This annealing has no effect in surface passivation indicating that a-SiCx:H films are promising candidates for c-Si surface passivation in the photovoltaic industry. In order to analyze the improvement of surface passivation after FGA, a physical model of surface recombination at the a-SiCx:H/c-Si interface is developed. This improvement is directly connected to a reduction in fundamental recombination velocities of electrons and holes at the interface. A possible explanation could be the reduction in the interface state density due to hydrogen saturation of dangling bonds.
CitationMartin, I., Vetter, M., Orpella, A., Puigdollers, J., Voz, C., Marsal, L., Pallarès, J., Alcubilla, R. Characterization and application of a-SiCx:H films for the passivation of the c-Si surface. "Thin solid films", Gener 2002, vol. 403-404, p. 476-479.