Konrad Schwanitz

Anti-reflective Silicon Oxide p-Layer for Thin-Film Silicon Solar Cells

A novel kind of microcrystalline silicon oxide (μc-SiO x (p):H) based p-layer has been developed at Applied Materials, Inc. over the last few years. This boron doped p-layer serves as a window and anti-reflective layer in micromorph (a-Si:H/μc-Si:H) tandem solar cells on ZnO substrates. Adjusting the refractive index in the range of 2–3.5 of the p-layer enables the use as a refractive index matching layer between ZnO (n ∼ 2) and silicon (n ∼ 4). This results in a significant decrease of reflection up to 3 %. As a consequence the short circuit current increases significantly in the silicon thin film solar cell device. In this chapter we show that the material properties of this new kind of p-layer are closely connected to the performance of the solar cells and even reduces the light-induced degradation (LID) of a-Si/μc-Si tandem junction cells.