Employing μc-SiO_x:H as n-Type Layer and Back TCO Replacement for High-Efficiency a-Si:H/μc-Si:H Tandem Solar Cells

摘要

The n-type hydrogenated microcrystalline silicon oxide (μc-SiO_x:H(n)) films with different stoichiometry have been successfully prepared by varying the CO_2-to-SiH_4 flow ratio in the PECVD system. By using the μc-SiO_x:H(n) as a replacement for μc-Si:H(n) and ITO, the conversion efficiency of μc-Si:H single-junction and a-Si:H/μc-Si:H tandem cells were improved to 6.35% and 10.15%, respectively. The major improvement of the short circuit current density (J_(SC)) and these cell efficiencies were originated from the increased optical absorption, which was confirmed by the quantum efficiency measurement showing increased response in the long-wavelength region. Moreover, the all PECVD process except the metal contact simplified the fabrication and might benefit the industrial production.