Sulfurization 온도와 Cu/(In+Ga) 비가 Cu(In,Ga)Se2 박막 내 S 함량에 미치는 영향

Abstract

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.