Influence of thermal annealing-induced molecular aggregation on film properties and photovoltaic performance of bulk heterojunction solar cells based on a squaraine dye

• Published in: Frontiers of materials science Vol. 12; no. 2; pp. 139 - 146
• Main Authors: ZHANG, Pengpeng, LING, Zhitian, CHEN, Guo, WEI, Bin
• Format: Journal Article
• Language: English
• Published: Beijing Higher Education Press 01.06.2018; Springer Nature B.V
• Subjects: Agglomeration; Annealing; Butyric acid; Chemistry and Materials Science; Dyes; Electrical properties; film properties; Heterojunctions; Materials Science; molecular aggregation; Molecular chains; Morphology; Optical properties; Organic chemistry; organic solar cells; Photovoltaic cells; power conversion efficiency; Radioactivity; Research Article; Solar cells; squaraine dye; organic solar cells; power conversion efficiency; squaraine dye; molecular aggregation; film properties
• DOI: 10.1007/s11706-018-0417-0
• ISSN: 2095-025X

Squaraine (SQ) dyes have been considered as efficient photoactive materials for organic solar cells. In this work, we purposely controlled the molecular aggregation of an SQ dye, 2,4-bis[4-(N,N-dibutylamino)-2-dihydroxyphenyl] SQ (DBSQ-(OH) 2) in the DBSQ(OH) 2:[6,6]-phenyl-C 61-butyric acid methyl ester (PCBM) blend film by using the thermal annealing method, to study the influence of the molecular aggregation on film properties as well as the photovoltaic performance of DBSQ(OH) 2:PCBM-based bulk heterojunction (BHJ) solar cells. Our results demonstrate that thermal annealing may change the aggregation behavior of DBSQ(OH) 2 in the DBSQ(OH) 2:PCBM film, and thus significantly influence the surface morphology, optical and electrical properties of the blend film, as well as the photovoltaic performance of DBSQ(OH) 2:PCBM BHJ cells.