In this study, we attempt the contribution of the silicon nanocrystal nc-Si luminescence phenomena to the performance of the conventional mc-Si solar cells. These nc-Si are embedded in the hydrogenated silicon nitride dielectric layers. The experimental results are obtained by different characterizations. They show that the optimum temperature is around 720°C with a good homogeneous distribution of nc-Si (3-5nm). However, to validate our results on silicon solar cells, we deposited silicon-rich silicon nitride layers on p-type (0.5ohm.cm) and diffused POCl3(40ohm/sq) substrates. Then, we performed thermal annealing at 720°C under mixture of gas (N2/H2) during one hour. The I-V measurements are carried out after the screen printing metallization and they showed 0.4% increase of the absolute efficiency.