title: Coating on a cold substrate largely enhances power conversion efficiency of the bulk heterojunction solar cell.
abstract: Spin-coating a mixture solution of P3HT and PCBM on a cold substrate largely enhanced the power conversion efficiency (PCE) of the bulk heterojunction (BHJ) solar cells. This concept was based on the abrupt decrease in the solubility of P3HT as solution temperature decreased. The selective precipitation of P3HT on the PEDOT:PSS-coated cold substrate facilitated a desirable rich composition of P3HT at the interface with the PEDOT:PSS layer. The high crystallinity of P3HT suppressed the movement of PCBM during thermal annealing, preventing aggregation of PCBM. The morphological excellence of the pristine film gave a comparable PCE to that made by the conventional fabrication process. After thermal annealing, the device made via coating on a cold substrate showed above 30% increase in PCE from the BHJ solar cells made by the conventional method.
authors.affiliation: Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seoul 120-749, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Oh
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Lee
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Myoung
authors.forename: Unyong
authors.initials: U
authors.lastname: Jeong
authors.forename: Hong Koo
authors.initials: HK
authors.lastname: Baik
mesh_terms: D011211:Electric Power Supplies; D037741:Fullerenes / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012993:Solar Energy; D012995:Solubility; D013696:Temperature; D013876:Thiophenes / Q000737:chemistry*
chemical_list: C539575:(6,6)-phenyl C61-butyric acid methyl ester; D037741:Fullerenes; D011108:Polymers; D013876:Thiophenes; C507295:poly(3-hexylthiophene)