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Layers of ethylene carbonate (EC) modified CuI/PVA polymer composites were prepared by growth of CuI nano-particles in an aqueous solution of PVA followed by casting at room temperature. The structural, thermal, optical, electrical and di-electrical characterization of polymer composites was investigated using different techniques. These investigations confirm the growth of CuI nano-particles and reduction of PVA crystallinity by increasing ethylene carbonate concentration. These results show that energy band gap and bulk conductivity increase while activation energy reduces with the increase of EC concentration in the composite. Moreover, the variation of the dielectric permittivity and dielectric loss with EC content are found to obey Debye dispersion relations.

a b s t r a c tAn important issue in construction of organic photovoltaic cells concerns the selective contacts. Here, especially the modification of the hole-extraction is challenging, as energy levels have to match the polymer's highest occupied molecular orbital (HOMO). We took the view to the mutual anode interface and we sought for a solution-based alternative for commonly used PEDOT:PSS -with an eye on improving the hole-extraction with an inorganic interlayer. We present copper iodide (CuI) as a versatile inorganic p-type semiconductor that meets the requirements for enhanced charge extraction in donor polymers. We applied two types of anthracene-containing PPE-PPV block-copolymers that recently gained attention as efficient active absorbers in bulk heterojunction photovoltaic cells. We report on the advantages using CuI as hole-selective contact and show an improvement of the power conversion efficiency in polymer-based solar cells.