Interface Engineering by Using Germanium Carbon Layer at the TCO/p Interface in Silicon Thin Film Solar Cells

We present a method based on using germanium carbon alloy as the TCO/p interfacial layer to enhance the performance of the silicon thin film solar cells and modules. The presence of the germanium carbon interfacial layer can minimize the potential barrier as well as the depletion width, which contribute to the improvement of FF and Voc; meanwhile, the loss in Jsc by previous methods can be eliminated due to the low parasitic absorption and index matching effect of the GeC film. We demonstrate significant improvement of the FF and Voc without loss in Jsc. The efficiency is enhanced by 7% for a-Si solar cell and the result is also successfully applied to the large area production of a-Si and a-Si/μc-Si modules.