Role of i layer deposition parameters on the V and FF of an a-Si:H

A study of the i-layer porosity as a function of the deposition parameters by PECVD technique, is presented here. It is demonstrated in particular, that for a fixed deposition rate of 2 Ays, increasing the plasma power tends to increase the layer ̊ density, while increasing the pressure tends to increase the layer porosity. Regarding the cells, no correlation between the layer density and the initial cell performances is observed. On the contrary, the i-layer porosity seems to influence the cell degradation: High porosity of the i-layer leads to high degradation, which gives an easy tool to investigate the layer quality.