Comparative studies of organic dyes with a quinazoline or quinoline chromophore as π-conjugated bridges for dye-sensitized solar cells

• Published in: Dyes and pigments Vol. 124; pp. 72 - 81
• Main Authors: Mao, Mao, Zhang, Xiaolin, Zhu, Bin, Wang, Jianbo, Wu, Guohua, Yin, Yan, Song, Qinhua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2016
• Subjects: Diphenylamine; Dye-sensitized solar cells; Electron-deficient; Quinazoline; Quinoline; Sensitizers; Quinoline; Dye-sensitized solar cells; Quinazoline; Electron-deficient; Diphenylamine; Sensitizers
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2015.09.002

A new series of organic D–π–A dyes bearing either quinazoline or quinoline as the conjugated bridges in the chromophore with a diphenylamine moiety as the electron donor and a cyanoacetic acid unit as the electron acceptor, have been designed and synthesized for photoconversion in dye sensitized solar cells (DSSCs). The absorption spectra, density functional theory calculations, electrochemical and photovoltaic properties of these dyes are systematically investigated. Among the four dyes the sensitized solar cell based upon the quinoline dye bearing butoxy groups gave a short circuit photocurrent density of 7.04 mA cm−2, an open circuit voltage of 0.52 V, and a fill factor of 0.69, corresponding to an overall conversion efficiency of 2.51% using I−/I3− redox couple-based liquid electrolyte without 4-tert-butylpyridine additives under standard global AM 1.5 irradiation (100 mW cm−2). The photovoltaic performance of the dye with 4,4′-dibutoxy diphenylamine as the donor and quinoline unit as the π-bridge was higher than that of the other photosensitizers, which is mainly attributed to the higher molar extinction coefficient and broader absorption band. The experimental results demonstrate that rational molecular engineering is crucial for constructing highly efficient charge transfer sensitizers. [Display omitted] •Four novel dyes with quinoline and quinazoline units as the π-bridges were designed.•4,4′-Dibutoxy diphenylamine unit as the donor leads to a better efficiency of DSSCs.•The highest cell efficiency was 2.51% for a quinoline-bridged dye.