Lara Perrin

Synthesis and properties of new soluble benzobistriazole photovoltaic polymers

We here report the synthesis of a new donor copolymer family based on benzobistriazole and dithienosilole. In the present work, the separation and purification of bromo-benzobistriazole isomers was realized for the first time, allowing the synthesis of a series of monomers with different positions of the solubilising alkyl chains. The thermal, photophysical and electrochemical properties of resulting synthesized copolymers are depicted. It should be noted that polymers with optical bandgaps ranging from 1.11 to 1.65 eV were obtained allowing to optimize the covering of the solar emission spectrum.

Extrusion as plausible processing method for production of organic photovoltaic solar cells

We present two polymers specifically designed for the preparation of extrudable solar cells. Extrusion is a clean, solventless process that might allow an inexpensive and large scale production of OPV cells. This plausible alternative to the usual techniques (printing, roll-to-roll...) could be considered to elaborate active layers based on two materials: donor (D) and acceptor (A). In order to achieve this, D and A polymers should possess similar viscosity. In addition the final materials need to retain controlled domains size, close to the exciton diffusion length, and continuous D and A paths. Commercial poly(3-octylthiophene) and synthesized fullerene-grafted polystyrene were chosen as D and A polymers, respectively. Their extrusion compatibility for PV application is verified for rheological and functional properties.