Amorphous hydrogenated silicon-nitride films for applications in solar cells

Abstract

The application of anti-reflective coatings (ARC) is a good method to improve the solar cell construction. The authors developed the RF plasma enhanced chemical vapour deposition method for preparation of amorphous silicon–nitrogen (a-Si:N:H) films for potential optoelectronic applications. The films have been obtained on borosilicate glass and monocrystalline silicon (1 0 0) (Cz–Si) in a process with optimised technological parameters such as a content of gaseous mixture of silane (SiH 4) and ammonia (NH 3). The properties of samples have been investigated by optical spectroscopy (PERKIN–ELMER Lambda 19) and scanning electron microscopy (SEM). The correlation between film properties and process parameters has been found. The results of optical investigations show that these materials are characterised by a variable optical gap dependent on the nitrogen content. After deposition of a-Si:N:H, a decrease in the total reflectivity, as compared to that of monocrystalline Si, was observed. The simulation of multicrystalline silicon solar cells performance with and without the ARC was done with the use of PC1D programme. The influence of the ARC on solar cell efficiency was observed. The obtained results indicate that a-Si:N:H films are suitable for application as antireflective and protective coatings for solar cells.