Multilayer rapid-drying blade coating for organic solar cells by low boiling point solvents

• Published in: Japanese Journal of Applied Physics 2014-06, Vol.53 (6), p.62301-1-062301-5
• Main Authors: Chen, En-Chen, Tsai, Pei-Ting, Chang, Bo-Jie, Wang, Chun-Ming, Meng, Hsin-Fei, Tsai, Jia-Ying, Chang, Yu-Fan, Chen, Zhi-Kuan, Li, Chang-Hung, Hsu, Yung-Hsuan, Chen, Chun-Yu, Lin, Hao-Wu, Zan, Hsiao-Wen, Horng, Sheng-Fu
• Format: Article
• Language: English
• Subjects: Annealing; Blade coating; Devices; Drying; Multilayers; Photovoltaic cells; Plating; Solar cells; Solvents
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.53.062301

A bulk heterojunction organic solar cell with poly(3-hexylthiophene) (P3HT) as the donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor is deposited using blade coating on a hot plate at 80 °C with hot air of 70 °C applied from above. In contrast to the 30 min of conventional dichlorobenzene solvent annealing, the rapid-drying blade coating forms a dry film in 1 s. The fabrication throughput is substantially enhanced. The blade-coated film has a smoother surface roughness of 3.5 nm compared with 10.5 nm for solvent annealing; however, the desired phase separation in the 50 nm scale forms despite the rapid drying. A single layer solar cell exhibits power conversion efficiency of 4.1% with blade coating in chlorobenzene, which is the same as solvent annealing device. A multilayer device with carrier blocking layers fabricated entirely of the less toxic toluene also exhibits efficiency of 4.1%.