https://scholars.lib.ntu.edu.tw/handle/123456789/408705
Title: | Metal-free branched alkyl tetrathienoacene (TTAR)-based sensitizers for high-performance dye-sensitized solar cells | Authors: | Ezhumalai Y. Lee B. Fan M.-S. Harutyunyan B. Prabakaran K. Lee C.-P. Chang S.H. Ni J.-S. Vegiraju S. Priyanka P. Wu Y.-W. Liu C.-W. Yau S. Lin J.T. Wu C.-G. Bedzyk M.J. Chang R.P.H. Chen M.-C. Ho K.-C. Marks T.J. |
Issue Date: | 2017 | Journal Volume: | 5 | Journal Issue: | 24 | Start page/Pages: | 12310-12321 | Source: | Journal of Materials Chemistry A | Abstract: | A new series of metal-free alkylated tetrathienoacene (TTAR)-based organic chromophores, TPA-TTAR-TA (R = branched-C8H17, 1, TTAR-b8; R = C15H31, 2, TTAR-15; R = C9H19, 3, TTAR-9), are synthesized for application in dye-sensitized solar cells (DSSCs). Due to the extensively conjugated TTAR £k-bridge, all three dyes exhibit high extinction coefficients (1 ¡Ñ 105 M-1 cm-1). By systematically exploring the effects of the TTAR alkyl chain substituents, a significant influence of the dye coverage (orientation) on the TiO2 surfaces is observed. The branched-alkyl TTAR-b8 (1) promotes significant tilting and packing distortion on TiO2 in comparison to more ordered monolayers of linear long alkyls TTAR-15 (2) and TTAR-9 (3). Photophysical measurements on the dye-grafted TiO2 films reveal that the branched-alkylated TTA unit in 1 enhances the electron injection efficiency, in agreement with the high quantum efficiency. Notably, by utilizing a three-dimensional (3D) photonic crystal (PhC) layer to enhance the coherent scattering an increase the light absorption, TTAR-b8 exhibits higher short-circuit current densities and achieved a high PCE of 11.18%. TTAR-b8 is thus the best performing fused-thiophene-based organic DSSC dye reported to date. ? 2017 The Royal Society of Chemistry. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/408705 | ISSN: | 20507488 | DOI: | 10.1039/c7ta01825h |
Appears in Collections: | 化學工程學系 |
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