Toward the fast deposition of highly crystallized microcrystalline silicon films with low defect density for Si thin-film solar cells

Abstract

In this study, employing a high-density, low-temperature SiH4–H2 mixture microwave plasma, we investigate the influence of source gas supply configuration on deposition rate and structural properties of microcrystalline silicon (μc-Si) films, and demonstrate the plasma parameters for fast deposition of highly crystallized μc-Si films with low defect density. A fast deposition rate of 65Å/s has been achieved for a SiH4 concentration of 67% diluted in H2 with a high Raman crystallinity of Xc>65% and a low defect density of (1–2)×1016cm−3 by adjusting source gas supply configuration and plasma conditions. A sufficient supply of deposition precursors, such as SiH3, as well as atomic hydrogen H on film growing surface is effective for the high-rate synthesis of highly crystallized μc-Si films, for the reduction in defect density, and for the improvement in film homogeneity and compactability. A preliminary result of p–i–n structure μc-Si thin-film solar cells using the resulting μc-Si films as an intrinsic absorption layer is presented.