Modelling Photoswitchable Organic-Graphene Hybrids

• Applicant: Professor Dr. Wolfgang Wenzel
• Subject Area: Synthesis and Properties of Functional Materials ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 279987564

MODIGLIANI targets the implementation of an integrated computational approach for the engineering of photochromic-graphene nanocomposite materials. More specifically, it will focus on the realization of graphene-based light-responsive field-effect transistors that will incorporate photo-responsive interfaces between graphene and either metallic (source, drain) electrodes or gate dielectrics. These interfaces will be tailored via chemisorption of highly ordered self-assembled monolayers of photochromic molecules. To guide synthetic and engineering efforts towards the best materials and devices, we will develop a multi-faceted and multi-scale modelling platform that fully integrates the description of (i) the structural organization, from the nano- to the meso-scale, and (ii) the light-triggered changes in their electronic structures in order to optimize (iii) the I-V characteristics of the graphene-SAMs based field-effect transistors (FETs) and (iv) the amplitude and response of the corresponding phototransistors upon light-induced switching as a function of the chemical composition. We will fully validate the theoretical results, at the respective length and time scales, against experimental microscopic and spectroscopic investigations and device testing. Once validated, the theoretical schemes developed during the project will be integrated as modules in a multiscale modelling environment aiming at becoming a predictive tool for end-users in academia and industry. Graphene has been touted as a miracle material owing to its combination of, among others, remarkable electrical, magnetic, optical and mechanical properties. MODIGLIANI will desig a new generation of graphene-organic hybrid materials exhibiting multifunctional properties. We will gain a deep understanding of the dynamic charge transfer and interfacial electrostatic effects of graphene using responsive molecules possessing a dipole moment, thereby allowing tuneable charge injection/extraction at interfaces. The unique combination of electronic and optical properties of the graphene-organic hybrids will be exploited to develop a new generation of light-switchable transistors. The profound fundamental understanding acquired during the project will pave the way to the design of new photochromic molecules and hybrid architectures to be used as active components in fast, efficient, and highly photoresponsive FETs. To reach these ambitious objectives, MODIGLIANI will rely on a skilful combination of modelling approaches including classical force-fields, quantum chemistry, solid-state physics and device modelling and their integration in a Computational Materials Engineering platform.

• DFG Programme: Research Grants
• International Connection: Belgium, France
• Cooperation Partners: Professor Dr. David Jacques Beljonne; Professor Dr. Frédéric Castet; Professor Dr. Paolo Samorì