6533b838fe1ef96bd12a38f9

RESEARCH PRODUCT

Synthesis of oligomers and polymers doped with porphyrins for solar energy conversion

subject

description

The aim of this thesis was to elaborate new electron donor materials for organic solarcells. This emerging photovoltaic technology is rapidly expanding, and has yet already reached the limit for its large-scale commercialization. The low manufacturing cost of organic photovoltaic devices make then competitive face to well-established inorganic technologies. Their biggest advantage is their weight and their mechanical properties which make them flexible. They should play a key role in future as a complement to classic solar cells, with their use in specific applications. We developed polymers by using different chomophores, well-known for their interesting photophysical properties: the porphyrin, the BODIPY and the diketopyrrolopyrrole. All these units intensively absorb the light, making them perfect candidates to be used to convert sunlight to electricity. By designing appropriate structures for this application, we synthesized several new promising polymers. Afterward, we studied their electrochemical and electronic properties, as well as their photophysics. We used powerful tools (streak camera, transient absorption, etc.) in order to understand in details their absorption and luminescence properties. These results enabled us to further understand their behavior once inside the active layer of photovoltaic devices. Indeed, the mechanism for the electric current creation involves ultrafast electron transfers (∼50 fs) toward electron acceptor. It is of utmost importance to understand and control parameters that could affect the electron transfer efficiency and the resulting charge stabilization, to finally lead to better power conversion efficiencies.