RAtional DEsign of blends for bulk heterojunction SOLar cells - RADESOL

Project summary

Within the research and technology field of organic electronics, organic photovoltaics (OPV) - based on either small molecule or polymer active materials – have recently shown substantial progress concerning performance of the solar cells produced and fundamental insights in device physics, architectures, lifetime and processing technology. The relevance of this emerging technology for future renewable energy production lies mainly in its potential to reduce the production cost per GigaWatt production volume in a substantial way. Processing of the required materials as inks using existing printing techniques and the limited demands on the production environment (no cleanrooms needed) allow for a cheap high-volume production of solar cells of medium efficiency. As only very thin films are used for the active layers (in the range of 100 nm) and various classes of organic materials can be applied, the cost advantages of such technology become even more clear. At this moment power conversion efficiencies (PCEs) above 10% can be envisaged for OPV and progress in device engineering has allowed for a first evaluation in real life, for the time being rather as a test-case in consumer electronics. To contribute substantially to resolving the TeraWatt energy challenge, many questions still need to be addressed, e.g. at the level of fundamental understandings, the development of the most effective device architectures, the use and role of specific interfaces and charge transport layers and implementation of the most economic production technology. The project proposal has as a main objective to achieve a more profound understanding on the molecular scale of the nanomorphology-performance relationship in active layer blends for bulk heterojunction (BHJ) organic solar cells and thus focuses specifically on the relationship between the molecular structures and supramolecular organization within the active layer and the device physics responsible for the solar cell performance. As such, the research activities involved concentrate on the synthesis of active organic materials, the study of the physicochemical properties of the active layer (components and blend), the morphological structure of the blend and the electro-optical characterization of devices prepared from these blends. As a direct impact of the project, a rational design of materials and active layers for OPV can be expected, providing a springboard for efficiency improvement of organic solar cells. The four partners (UHasselt, VUB, NTNU and IT) from three European countries (Belgium, Norway and Portugal) have all well-documented research activities in the field of organic electronics and more in particular OPV. The numerous contributions of said research groups relate to all the different aspects needed to make fundamental progress in the field. A highly complementary and interdisciplinary team is gathered in the consortium and a high level of synergy in the research activities can be achieved. As a direct benefit of the project, the scientific know-how within the European organic electronics community will be reinforced. The objective of the proposal comprises a very critical and fundamental aspect toward further progress in the performance of organic solar cells. Furthermore, all partners are strongly integrated in the existing research networks around OPV, with key research groups in Belgium, the Netherlands, UK, Sweden, Denmark, Germany, France and Spain. Indirectly, the results of this research will certainly disseminate into collaborations with research partners in these countries.