Aug 22 2013
The excellence of the research performed at EPFL has once again been recognized at an international level. Kevin Sivula has been awarded a STARTING GRANT 2013 from the European Research Council (ERC).
© 2013 EPFL
Crystal Engineering for Molecular Organic Semiconductors
The urgent need to develop inexpensive and ubiquitous solar energy conversion cannot be overstated. Solution processed organic semiconductors can enable this goal as they support drastically less expensive fabrication techniques compared to traditional semiconductors. Molecular organic semiconductors (MOSs) offer many advantages to their more - common π - conjugated polymer counterparts, however a clear and fundamental challenge to enable the goal of high performance solution - processable molecular organic semi conductor devices is to develop the ability to control the crystal packing, crystalline domain size, and mixing ability (for multicomponent blends) in thin - film devices. The CEMOS project will accomplish this by pioneering innovative methods of “bottom-up” crystal engineering for organic semiconductors. We will employ specifically tailored molecules designed to leverage both thermodynamic and kinetic aspects of molecular organic semiconductor systems to direct and control crystalline arrangement, promote cry stallite nucleation, compatibilize disparate phases, and plasticize inelastic materials. We will demonstrate that our new classes of materials can enable the tuning of the charge carrier transport and morphology in MOS thin films, and we will evaluate their performance in actual thin-film transistor (TFT) and organic photovoltaic (OPV) devices. Our highly interdisciplinary approach, combining material synthesis and device fabrication/evaluation, will not only lead to improvements in the performance and stability of OPVs and TFTs but will also give deep insights into how the crystalline packing—independent from the molecular structure—affects the optoelectronic properties. Overall, the classes of materials CEMOS will develop represent ground-breaking new concepts in solution processable organic semiconductors. The success of CEMOS will rapidly advance the performance of MOS devices, and —given their intrinsic advantages— will drive a paradigm shift to the widespread use of MOSs. This will enable reproducible and comparable performance in solar energy conversion devices with respect to traditional semiconductors— but at radically lower processing costs.