The vividly developing field of plasmonics aims - among others - to explore surface plasmon resonance related phenomena in plasmonic nanocrystals (NCs) and their potential applications. State-of-the-art chemical methods allow design and fabrication of the NCs and their 2D assemblies with tailored spectral properties, which can conveniently be used to introduce an optical handle to the system of interest. Merging the plasmonic and magnetic nanoworlds offers a rich variety of multi-responsive and multi-functional nanosystems, where, via absorption of light by plasmons, magnetic properties of matter can be modified. The mainstream of this research focuses, however, on light induced changes of static magnetic properties. Controlling/triggering spin currents (or spin dynamics) with external stimulus such as continuous low-power white light (and not ultrashort high-power laser pulses), even though very promising, so far attracted very limited attention. In other words, whereas corresponding light-driven or light-mediated processes in the field of electronics are well studied and broadly utilized (e.g. solar cells or light emitting diodes), very little is known about the possible role of such light in the field of spintronics and spin dynamics. Hence, the general goal of this project is to explore the role of plasmon-mediated processes in the excitation and influencing of magnetization dynamics (plasmon-mediated spindynamics), with final (long-term) goal being to influence/drive nanometer spin waves (magnons) with visible light. For that purpose, NCs of desired optical properties will be fabricated and arranged on the surface of thin ferromagnetic films in such a way that light sensitivity of as prepared hybrid structures will serve as an optical handle to induce/affect the precessional motion of spins in a ferromagnetic layer (spin dynamics). Ferromagnetic resonance will probe the magnetization dynamics in the frequency domain, where the sample illumination, resulting in the surface plasmon resonance excitation of NCs, is expected to either damp or anti-damp the precessional motion of spins and/or shift the ferromagnetic resonance frequency, thereby allowing the use of light for controlling dynamic magnetic properties of such system. At the same time, magnetization dynamics in these hybrids will be studied in time domain using time-resolved magneto-optics. Terahertz magnons generated by pulses of terahertz radiation are expected to be affected (precessional amplitude, frequency, decay time) by surface plasmons simultaneously excited due to absorption of light. Additionally, the generation of terahertz magnons is explicitly expected via plasmon excitation using femtosecond laser pulses. This way, a detailed mechanistic picture of magnon excitations at GHz to THz frequencies within the hybrid structures under illumination will be obtained.

Scientifically and technologically, but also economically, dye chemistry has represented a major field of activity in chemical industry and academic research since the 19th century. Nowadays, dye sciences are facing new exciting challenges. Given the announced shortage in fossil fuels, alternative energy supplies such as photovoltaics represent realistic solutions that require efficient materials for sun photons capture and conversion into electricity. Among the vast majority of dye families, those combining electron donor (D) and acceptor (A) groups, such as D-A dipolar compounds, occupy a central place because presence of alternating electron-rich/electron-deficient units reduces the bandgap and facilitates intrachain charge transfer. First incorporated into polymeric backbones, the D-A concept has now gained much interest with the recent discovery that low molecular weight dye structures with a net dipole moment can lead to the rational design of new active materials for organic solar cells. Therefore, the in-depth investigation of both optical and electronic properties of low molecular weight D-A molecules in the solid-state represents a fundamental challenge of tremendous importance in view of assessing the performance of new generations of low band gap materials. Moreover there is still a critical need for the design of small molecular semiconductors in order to further explore structure-property correlations and ultimately overcome the technological barriers that concern cost-effective materials, easy processability, large-area device efficiency, and end-products mass production. This project proposes a rational study based on the implementation of chalcone and curcuminoid dyes in which borondifluoride complexation is used as a simple way to impart the molecular structure with extremely strong ground- and excited-state dipole moments. Such systems have the D-A and D-A-D structures, respectively. A preliminary study showed chalcones compounds display promising photovoltaic properties when used as donor materials in the presence of [6,6]phenyl-C61-butyric acid methyl ester (PC61BM) in bulk heterojunction solar cells. The project aims at unravelling the factors that control solar cell efficiency combining chemical, spectroscopic, theoretical, and technological approaches. It includes the synthesis of new dyes with optimized electronic energy levels, improved charge transport properties, and allowing the control of thin film morphology at the nanoscale. Quantum chemical calculations will be used to unravel structure-properties, and next, to predict the spectroscopic features of new molecular structures. Device fabrication will allow identifying the best candidates and will focus on the optimization of efficient solution-processed single junction. In a final stage, materials with the best photovoltaic performance will be tested in the fabrication of large area solar cells using an industrial prototype for solution printing, which will need the development of ink formulation. The project gathers three academic teams, two of chemists – experimental and theoretician – and one of physicists, and an industrial partner. This project is mainly devoted to chalcones. Indeed these compounds can be obtained via simple, efficient preparation and easy purification procedures. They represent archetypal examples of organic compounds that can be obtained according to green chemistry, such as in solvent-free reactions. Ultimately, a long-term goal would be to identify the potential of the novel molecular structures in advanced applications with the idea of fostering green chemical approaches.

Porphyrins are the most important and adaptable macrocycles in science since their research concerns areas ranging from chemistry to materials science, physics to biology and engineering to medicine. In 2013, the two groups implied in the present proposal have been the first to report a “pyrrol-free” porphyrin azaanalogue, named azacalixphyrin, which revealed unique fundamental properties. This joint experiment-theory proposal aims to rapidly assess the properties of these new extremely promising but yet unexplored macrocycles as novel tools for science. We are mainly focussed in two specific directions: on one hand, after having explored the impact of side substitutions we will synthesize an optimal fused dimer whereas, on the other hand, several metallation patterns will be tested and characterized. According to preliminary results, remarkable electronic properties are expected for all these new molecular architectures (metal-metal interactions, absorption and emission in NIR region). We are conviced that EMA will allow the appearance of new concepts for fundamental studies but will also pave the way for new technological applications relying on improved dyes. We can thus envision for these new compounds exceptional versatility in science by analogy to porphyrins.