efficient sOluble small molecules foR photovoltaIc applicatiONs – ORION

The multidisciplinary ORION project involves three partners who have been collaborating since already several years. The first partner is specialized in the synthesis of semiconducting materials for organic photovoltaic applications (N. Leclerc team from ICPEES). The second partner is specialized in the synthesis of molecular organic fuorophores and fast electron transfer processes (R. Ziessel team, ICPEES laboratory). The third partner is recognized for its expertise in the elaboration and advanced characterization of organic photovoltaic devices (T. Heiser team, Icube).
The ORION project relates to the first main topic of the PROGELEC program (photovoltaic energy production) and addresses more specifically the sub-theme 1.2 (thin films devices) by targeting the increase of the power conversion efficiency as well as the stability of organic solar cells.
The ORION project aims to elaborate efficient and stable solar cells (power conversion efficiency of the order of 9%) from soluble electron donor small molecules.
In the first part of the project, the partners will investigated and to circumvent photovoltaic performance limitations observed during preliminary studies on two original chemical platforms: the boron dipyrromethene (BODIPY) and the triazatruxene (TAT). Each platform allowed the present consortium to reach already power conversion efficiencies in the 5% range. The first part of the ORION project is dedicated to identify and overcome the limiting factors and to enhance the power conversion efficiency up to an expected 9% (according to Scharber’s semi-empirical model). This part involves both partners for either the synthesis of new molecules (with broad absorption spectra, strong absorption coefficients and efficient intermolecular charge transport) and for the advanced physical characterization of already synthesized or newly designed molecules (charge transport, bimolecular recombination rate and photovoltaic properties).
In the second part of the project, the partners will target an enhanced stability of the photovoltaic devices active layer. This more fundamental research part will be based mainly on the TAT platform and the basic idea is to promote supramolecular interactions either between the soluble donor small molecules or between the electron donor and the electron acceptor (PCBM derivative) constituents. These supramolecular interactions are expected to stabilize the active layer. Different ideas will be explored involving the chemical synthesis of functionalized soluble electron donor small molecules and/or PCBM derivatives. These advanced chemical synthesis concepts will be experimentally confirmed by photovoltaic devices lifetime measurements. This second part also involves both partners of the ORION project.