Dangling Bonds Parameters Effect on Dark and Illuminated Conductivity in a-Si:H Absorber Layer for Solar Cells Applications

In this paper, a contribution is made to study the impact of the DOS (Density of States) defects in undoped a-Si:H on the conductivity in the dark and under solar illumination. The quality of this material is the key to the best PV efficiencies reached in the solar cells based on a- Si:H, used as an absorbing layer between two heavily doped regions. There is a strong correlation between the PV output and the quality of this region for an optimal thickness. It has been widely shown that PECVD and HWCVD techniques lead to a growth of silicon with a high density defects in its forbidden band and usually described by two decreasing exponential distributions for the valence and the conduction band tail (BT) and two correlated Gaussian distributions for deep defects introduced by dangling bonds (DB).