Carbazole-based small molecule electron donors : syntheses, characterization, and material properties
Sippola, Roosa J.; Hadipour, Afshin; Kastinen, Tuuva; Vivo, Paola; Hukka, Terttu I.; Aernouts, Tom; Heiskanen, Juha P. (2017-11-08)
Roosa J. Sippola, Afshin Hadipour, Tuuva Kastinen, Paola Vivo, Terttu I. Hukka, Tom Aernouts, Juha P. Heiskanen, Carbazole-based small molecule electron donors: Syntheses, characterization, and material properties, In Dyes and Pigments, Volume 150, 2018, Pages 79-88, ISSN 0143-7208, https://doi.org/10.1016/j.dyepig.2017.11.014
© 2017 Elsevier Ltd. All rights reserved. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.
Efficient synthetic methods for carbazole-based small molecule electron donors with donor–acceptor (D–A) and A–D–A type structures were developed. In order to study the relation between chemical structures and material properties, the prepared compounds were characterized in detail using absorption spectroscopy, differential pulse voltammetry, and computational methods. In addition, symmetrical A–D–A type compounds were tested as an active layer component in bulk heterojunction based organic solar cell (OSC) devices with conventional structure. The results show that the two compound types have many similar properties. However, the extended molecular structure of A–D–A type compounds offer better film forming properties and higher molar absorption coefficients compared with the D–A type materials. Furthermore, the attachment of fluoro substituents in the A units has a positive effect on all solar cell device parameters. Moreover, the computational studies revealed that the molecular structures are twisted between the central carbazole D unit and π-bridge which may result in inefficient intramolecular charge transfer and, also, relatively limited short-circuit currents in OSC devices.
- Avoin saatavuus