We examine the effects of light‐induced degradation in material properties of a‐Si:H upon the device physics of an a‐Si:H p+in+cell. It is shown that the increase in defect density upon degradation can lead to a significant decrease in electric field over middle regions of the i layer. This decrease is particularly severe under forward bias (near the maximum power point), and can explain the degradation in fill factor of the cell upon light soaking. We show that by using an innovative cell design, with graded gap i layer, we can increase field inthe middle regions, and reduce the degradation in fill factor.