Fabrication of nc-Si:H n-i-p single-junction solar cells using VHF PECVD at a deposition rate of 10 Ã\x85/s

Efforts on the fabrication and optimization of hydrogenated nanocrystalline silicon (nc-Si:H) solar cells using VHP PECVD technique in our UT multi-chamber load-locked PECVD deposition system at a high deposition rate of 10 Aring/s are reported in this paper. nc-Si:H n-i-p single-junction solar cells with initial active-area (0.25 cm²) efficiencies of about 6.6% have been obtained with an i-layer deposition time of 25 min corresponding to a thickness of about 1500 nm and an short circuit current density J_sc of about 21 mA/cm². The deposition conditions for n-layer and p-layer have also been optimized for the VHP nc-Si:H nip solar cells. With these optimizations, the best FF value of the VHP nc-Si:H single-junction solar cells was reached at 70.9% with an initial efficiency of eta=6.56%. The QE curve shows that the as-deposited nc-Si:H cell has a good spectral response in the long wavelength range and yields an AM1.5G integrated current density J_sc of 8.38 mA/cm² over the wavelength region from 650 nm to 1000 nm, which is a good candidate as bottom component cell in a-Si:H/a-Si:H/nc-Si:H triple-junction solar cell