The thickness effect of SiOx layer in CIGS thin-film solar cells fabricated on stainless-steel substrate

We have investigated the thickness effect of SiO_x layer in the CIGS thin-film solar cells fabricated on stainless-steel substrate. After a SiO_x layer with a thickness of 1 or 2-μm was deposited on the substrate by using plasma-enhanced chemical vapor deposition, Na-doped Mo layer and Mo layer were coated on it. A CIGS thin-film solar cell on the stainless-steel substrate without the SiO_x layer showed an efficiency of 7.47 %, the solar cell with the 1 μm-thick SiO_x showed an efficiency of 11.82 %, and the solar with the 2 μm-thick SiO_x showed the efficiency of 12.43%. The efficiency of CIGS solar cell with 2 μm-thick SiO_x was higher than those of others with the thinner SiO_x barrier.