Influence of n-type layer structure on performance and light-induced degradation of n-i-p microcrystalline silicon solar cells

A series of n-i-p microcrystalline silicon thin film solar cells with different values of crystalline volume fraction Xc of n-type layers are prepared by radio frequency plasma enhanced chemical vapor deposition. It is found that the structure of intrinsic layer is strongly dependent on the structure of n-type layer, especially the incubation layer thickness at n/i interface and Xc of intrinsic layer. This series of solar cells were light-soaked under 100 mW/cm2 for 400 h. The experiment results demonstrate that the solar cell with the highest Xc of intrinsic layer (Xc(i)=65%) has the lowest light-induced degradation ratio. Then the solar cell with n-type layer deposited in an amorphous silicon/microcrystalline silicon transition region (Xc(i) =54%) is light-soaked under the irradiations of white light, red light and blue light with the same light intensities, separately. After 400 h light-soaking, the light degradation ratio is only 2% for the red light irradiation, while it is 8% for the blue light irradiation.