Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

It is known that sulfide at the Cu(In,Ga)Se₂ (CIGSe₂) surface plays a positive role in CIGSe₂ solar cells. We investigated the substitution of S with Se on the CIGSe₂ surface in S atmosphere. We observed that the sulfur content in the CIGSe₂ films changed according to sulfurization temperature and Cu/(In+Ga) ratio. The sulfur content in the CIGSe₂ films increased with increasing the annealing temperature and Cu/(In+Ga) ratio. Also Cu migration toward the surface increased at higher temperature. Since high Cu concentration at the CIGSe₂ surface is detrimental role, it is necessary to reduce the S annealing temperature as low as 200°C. The cell performance was improved at 200°C sulfurization.