Abstract

Four D-π-A dyes (D=donor, A=acceptor) based on a 3,4-thienothiophene π-bridge were synthesized for use in dye-sensitized solar cells (DSCs). The proaromatic building block 3,4-thienothiophene is incorporated to stabilize dye excited-state oxidation potentials. This lowering of the excited-state energy levels allows for deeper absorption into the NIR region with relatively low molecular weight dyes. The influence of proaromatic functionality is probed through a computational analysis of optimized bond lengths and nucleus independent chemical shifts (NICS) for both the ground- and excited- states. To avoid a necessary lowering of the TiO2 semiconductor conduction band (CB) to promote efficient dye-TiO2 electron injection, strong donor functionalities based on triaryl- and diarylamines are employed in the dye designs to raise both the ground- and excited-state oxidation potentials of the dyes. Solubility, aggregation, and TiO2 surface protection are addressed by examining an ethylhexyl alkyl chain in comparison to a simple ethyl chain on the 3,4-thienothiophene bridge. Power conversion efficiencies of up to 7.8 % are observed.

Department(s)

Chemistry

Publication Status

Full Access

Comments

National Science Foundation, Grant EPS-0903787

Keywords and Phrases

dye-sensitized solar cells; NICS; proaromaticity; solvatochromism; thienothiophene

International Standard Serial Number (ISSN)

1521-3765; 0947-6539

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Wiley, All rights reserved.

Publication Date

11 Jan 2016

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Chemistry Commons

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