New polymer materials for organic photovoltaics

This project focuses on synthesis of new polymer materials for organic photovoltaics which ensure high efficiency, high stability which are processable with a fast and cheap printing method. This is carried out by designing and preparing polymer materials with focus on low band gap and side chains.

Low band gap has the ability to increase the maximum current obtainable for the device and hence increase the efficiency. Types of low band gap polymers are shown in Figure 1.

Types of low band gap polymers based on a donor (red) and an acceptor (blue) unit

Figure 1: Types of low band gap polymers based on a donor (red) and an acceptor (blue) unit.1

Thermocleaveble side chains have been shown to increase the stability of the photovoltaic device, since an insoluble film is formed once the organic layer is heated as shown in Figure 2.

Figure 2: Princip of the thermocleavable side chains
Figure 2: Princip of the thermocleavable side chains.2

As written the side chains make the polymer material soluble and hence it is possible to prepare the device by printing the organic layer, i.e. screen or pad printing, making the preparation of large area devices both cheaper and faster.

The results achieved in the project will be published in papers and will be announced on this web-page.

Reference:
  1. a) E. Bundgaard, F. C. Krebs, Sol. Ener. Mater. Sol. Cells 2007, 91, 954-985
    b) D. Mühlbacher, M. Scharber, M. Morana, Z. Zhu, D. Waller, R. Gaudiana, C. J. Brabec, Adv. Mater. 2006, 18, 2884-2889.
  2. F. C. Krebs, H. Spanggard, Chem. Mater. 2005, 17, 5235-5237.

The project is funded by Danich Agency for Science Technology and Innovation [274-08-0057].

Page updated  by   21.12.2011


Eva Bundgaard
Scientist
Solar Energy Programme (SOL)
Dir tel+45 46775498