Modeling of the Effect of p-Layer and i-Layer Properties on the Electrical Behaviour of a-Si:H/a-SiGe:H Thin Film Hetero-Structure Solar Cell

In amorphous thin film p-i-n solar cell, a thick absorber layer can absorb more light to generate carriers, however, a thicker i-layer degrades the drift electric field for carrier transport. On the other hand, a thin i-layer cannot absorb enough light. So Thickness of i-layer is a key parameter that can limit the performance of amorphous thin film solar cells. On the other hand, introducing Ge atoms to the Si lattice in Si-based solar cells is an effective approach in improving their characteristics. Especially, current density of the cell can be enhanced without deteriorating its open circuit voltage. This work presents a novel numerical evaluation and optimization of amorphous silicon double junction (a-Si:H/a-SiGe:H) thin film solar cells and focuses on optimization of a-SiGe: H mid-gap single junction solar cell based on the optimization of the Ge content in the film, thicknesses of the i-layer and p-layer, and doping concentration of the films.