The application of low-frequency glow discharge to high-rate a-Si:H deposition [solar cells]

Using the low frequency (55 kHz) glow discharge technique (LF PECVD), the a-Si:H solar cell thin films were deposited with high growth rate (up to 25 Å/s) and good electronic and optical properties in spite of inhomogeneous structure. In this work, the authors investigated the plasma properties and the film structure to clarify the mechanisms controlling the growth rate. The plasma and the films were investigated with using of optical emission spectroscopy, IR-spectroscopy and atomic force microscopy. It is concluded that the increase of deposition rate in LF glow discharge is caused by the increased flux of SiH_n radicals due to approach of SiH₄ decomposition range to film growth surface, whereas the ion bombardment of growing film provides device quality electronic properties