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Structure-Function Relationship in Polymer Solar Cells
Organic solar cells typically consist of several components and it is long recognised that their efficiency depends on the detailed morphology of these constituents. Structure formation in two components systems, often containing a conjugated polymer and a C60 derivative, is currently not well understood and the their detailed characterisation is complicated by the low contrast in scattering and microcopy. In this presentation, a model for structure formation in several polymer photovoltaics blends will be presented. Our experimental results are consistent with structure formation driven by the crystallisation of the conjugated polymer (often poly(3-hexylthiophene)) causing the formation of a an hierarchical interdigitated morphology. It is likely that the details of this structure formation process lies at the origin of the electronic properties of photovoltaic devices based on these materials.