Impact of Hydrogen Plasma Treatment on Intrinsic Amorphous Silicon Bilayers in Silicon Heterojunction Solar Cells

We demonstrate the impact of the intermediate hydrogen plasma treatment of intrinsic amorphous silicon layer in silicon heterojunction solar cells (SHJ). After deposition of the first layer of intrinsic amorphous hydrogenated silicon with a thickness of 5–6 nm hydrogen plasma treatment allows passivation of defects in the layer and, due to surface hydrogenation, creates conditions for defect-free growth of the next layer to a total thickness of 10 nm. The lifetime of minority charge carriers increases from 2 to 5 ms in comparison with base process. The parameters of hydrogen plasma treatment are determined, which makes it possible to increase the surface passivation quality by the layers of intrinsic hydrogenated amorphous silicon in the production of high-efficiency solar cells. The process is useful for fabrication of high performance SHJ solar cells.