Effects of chlorine and carbon on Cu2ZnSnS4 thin film solar cells prepared by spray pyrolysis deposition

J-V curves for solar cells with CZTS absorption layer deposited by SPD. No. 1 Cl-contained, with pre-anneal, 7 coatings. No. 2 Cl-free, with pre-anneal, 7 coatings. No. 3 Cl-free, with pre-anneal, 14 coatings (to deposit thick film). No. 4 Cl-free without pre-anneal (to reduce Carbon), 14 coatings (to deposit thick film). No. 5 Cl-free without pre-anneal (to reduce Carbon), 14 coatings (to deposit thick film) and aligned buffer layer deposition process.141