Multi-junction cells

The multi junction cell to cover range of spectrum. 

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. 

Advancing the Efficiency of Solution Processed Multi-Junction Cells... 

A further increase in the efficiency of polymer solar cells can be achieved by extending the multi-junction configuration from two to three or more photoactive layers. Multi-junction cells with more than two absorber layers are readily obtained using thermal evaporation of photoactive and... 

Polymer multi-junction cells have also achieved noticeable attention. In Table 11.2 we provide an overview of the multi-junction cells that had been published up to the end of 2014. In 2007, Gilot et al showed that it is possible fully to solution process three photoactive layers and two recombination layers based on ZnO/PEDO PSS and obtain a working triple junction solar cell with koc = 2. 19 By the same procedure, six-fold junction cells with... 

The improvements described above have been obtained via the design and development of new semiconducting polymers, with wide, medium, and small bandgaps, and by the improvement of the interconnecting layers in regular or inverted series-connected multi-junction cells. In addition to the... 

Tandem or multi-junction cells are built with two or more subcells (absorbing in different wavelength) arranged in stacks. From the point of view of electrical performance they may be considered connected in series, with the voltage given by the sum of subcell voltages and the current limited by the... 

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