The effects of siloxane bearing side-chains on the photovoltaic performance of conjugated polymers
Gaël Heintges a b, Koen Hendriks a, Mengmeng Li a, Fallon Colberts a, René Janssen a c
a Molecular Materials and Nanosystems, Eindhoven University of Technology, Netherlands, Netherlands
b Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek, Belgium
c DIFFER – Dutch Institute for Fundamental Energy Research, the Netherlands, De Zaale, 20, Eindhoven, Netherlands
International Conference on Hybrid and Organic Photovoltaics
Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV18)
Benidorm, Spain, 2018 May 28th - 31st
Organizers: Emilio Palomares and Rene Janssen
Poster, Gaël Heintges, 283
Publication date: 21st February 2018

In the field of organic solar cells, conjugated polymers with a push-pull design have extensively been developed for use as electron donors in the active layer of these devices. Most of these polymers contain alkyl side-chains to ensure solubility in common organic solvents. In this work, we explore the possibility of introducing siloxane groups in the side-chains, hereby altering the aggregation tendency of the polymer and influencing the morphology of the active layer when these materials are used in solar cell devices.

As a model system HD-PDPPTPT, a well-known DPP based polymer in our group, was selected. When substituting all alkyl chains for siloxane containing chains an immediate decrease in solubility is observed, along with a decrease in molecular weight, leading to the interesting situation where the trend in molecular weight is reversed to the trend in solubility. In solar cells, a sharp decrease in short circuit current is associated with increasing siloxane content, which is correlated to a reduced fluorescence quenching efficiency. Morphological studies show however no big differences between the active layers with siloxane containing polymers and active layer with alkyl side-chains on the polymer. Interestingly, a direct correlation between the solar cell performance and molecular weight could be established, whereas previously a relation between solar cell performance and morphology on one hand, and solubility on the other hand was hypothesized. In this way, this material system can provide more insight in morphology formation and the role of solubility and molecular weight on the solar cell performance.

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info