Tandem polymers

J. Y. Kim, K. Lee, N. E. Coates, D. Moses, T.-Q. Nguyen, M. Dante, A. J. Heeger, Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing. Science 2007,317,222-225. 

A.F. Mitul, et al. Low temperature efficient interconnecting layer for tandem polymer solar cells. Nano Energy, 2015.11 p. 56-63. 

J. Yang, et al, A robust inter-connecting layer for achieving high performance tandem polymer solar cell. Advanced Materials, 2011. 23 p. 3465-3470. 

L. Don, et al.. Tandem polymer solar cells featuring a spectrally matched low-bandgap polymer. Nature Photonics, 2012. 

L. Dou, et al.. Systematic investigation of benzodithiophene- and diketopyr-rolopyrrole-based low-bandgap polymers designed for single junction and tandem polymer solar cells. Journal of the American Chemical Society, 2012. 134(24) p. 10071-10079. 

J.Y. Kim, et al.. Efficient tandem polymer solar cells fabricated by all-solution processing. Science, 2007. 317 p. 222-225. 

Several excellent reviews exist on polymer tandem solar cells and we refer to these publications for a comprehensive overview. In this chapter we focus on the materials requirements for creating efficient polymer solar cells and intermediate contact layers. In the following paragraphs, we will outline the operational principles in more detail. We will then review the most important photoactive materials used in polymer multi-junction cells and outline the material combinations that can used for the recombination layer. We conclude with an overview of recent achievements that have pushed the efficiency to well over 10% and address the progress in processing of large area tandem polymer solar cells. 

Over the last decade there has been enormous progress in tandem polymer solar cells. Advances have been made in terms of understanding, new photoactive materials, new interlayers, and device configurations (regular vs. inverted, parallel, semitransparent, etc). In Table 11.1 we provide a list of results obtained up to the end of 2014, following a more or less historical perspective and giving preference to listing the more salient results in terms of PCE. Table 11.1 lists the materials used in the front and back subcell. 

Table 11.1 Solution processed tandem polymer solar cells.

Following the demonstration of solution processed tandem polymer solar cells in 2007, the performance of these devices has developed significantly. In this section, we highlight some of the advances made since then. 

In a comprehensive study, Brabec and Krebs et al. have addressed a cost analysis for single junction and tandem polymer solar cells based on... 

In 2010, Yang et al published the first inverted configuration tandem polymer solar cell using P3HT PC6iBM and PSBTBT PC7iBM subcells. As a recombination layer, Yang et al used thermally evaporated MoOj and Al, covered with a sol-gel ZnO layer to reach a PCE of 5.1%. Almost at the same... 

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