Chemical compatibility between a hole conductor and organic dye enhances the photovoltaic performance of solid-state dye-sensitized solar cells

• Published in: Journal of materials chemistry 2012-01, Vol.22 (17), p.8641-8648
• Main Authors: Kwon, Young Soo, Lim, Jongchul, Song, Inwoo, Song, In Young, Shin, Won Suk, Moon, Sang-Jin, Park, Taiho
• Format: Article
• Language: English
• Subjects: Conductors (devices); Conversion; Dyes; Electrodes; Photovoltaic cells; Solar cells; Surface properties; Titanium dioxide
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c2jm30215b

A series of organic dyes having an unsymmetrical geometry, 3-(5'-{4-[(4-tert-butyl-phenyl)-(4-fluoro-p henyl)-amino]-phenyl}-[2,2']bithio-phenyl-5-yl)-2-cyano-acryl ic acid (D-F), 3-(5'-{4-[(4-tert-butyl-phenyl)-p-tolyl-amino]-phenyl}-[2,2'] bithiophenyl-5-yl)-2-cyano-acrylic acid (D-CH sub(3)), and 3-(5'-{4-[(4-tert-butyl-phenyl)-(4-methoxy- phenyl)-amino]-phenyl}-[2,2']bithiophenyl-5-yl)-2-cyano-acryl ic acid (D-OCH sub(3)), were designed and synthesized for use in solid-state dye-sensitized solar cells (sDSCs). The dye regeneration energy levels and surface properties were characterized to determine the hole transfer yield from the oxidized dye to the hole conductor (spiro-OMeTAD) by measuring the degree of pore-filling by the spiro-OMeTAD and the transient absorption spectra (TAS). An electrode sensitized with D-OCH sub(3) exhibited the highest spiro-OMeTAD filling fraction and hole transfer quantum yield ( Phi ) to spiro-OMeTAD, resulting in an enhanced photocurrent and a power conversion efficiency of 3.56% in the sDSC, despite a lower energy driving force for hole transfer compared to those of D-F, or D-CH sub(3). This result illustrates the importance of the chemical compatibility between the hole conductor and the dye on the surface of TiO sub(2).