Improvement of a-Si:H Thin-film Solar Cells by Employing Large Ag Nanoparticles

Silver (Ag) nanoparticles were formed on fluorine-doped tin oxide (FTO) coated glass substrate, and then hydrogenated amorphous silicon (a-Si:H) thin-film solar cells were sequentially fabricated. Ag nanoparticles located in the interface between the FTO and the p-layer leads to a light-trapping effect because of the strong light-material interaction in Ag nanoparticles and enhancement of the optical path length. A higher haze ratio appeared for Ag nanoparticles with larger diameters and heights, compared with the conventional type. The device with the Ag nanoparticles showed a short-circuit current density of 12.66 mA cm−2, which was 2.2 mA cm−2 higher than the device without Ag nanoparticles. Conversion efficiency increased from 4.9 % to 5.9 % by employing Ag nanoparticles with a roughness of 71 nm. The simple process makes our design useful for low-cost, high conversion efficiency thin-film solar cells.