Photonics - Research Activities

Solar Energy Conversion

We investigate photoactive molecular/supramolecular systems and nanomaterials exhibiting harvesting of solar light, photoinduced energy and electron transfer processes, photoluminescence. Our objective is a deep understanding of the fundamental processes that enables the design of efficient devices that convert sunlight to fuels (e.g., H2, CO, CH4) and/or electricity (OPV and perovskite cells, DSSCs, luminescent solar concentrators).
(read more...)

Luminescent Materials

We synthesize and characterize the optical properties of luminescent materials such as organic molecules, polymers, transition metal complexes, MOFs and organic crystals both in solution and in the solid state. These materials are typically used in electroluminescent devices and fluorescent sensors.
(read more...)

Optoelectronic Devices

Organic light emitting devices have been the focus of our research since many years.
A special attention is devoted to find out luminescent compounds with high quantum yields to be exploited as efficient emitters in OLEDs. Cyclometalated organic complexes of heavy metals -Pt(II) and Ir(III) in particular- together with Cu(I) organic and hybrid complexes are the major interests of our research activity and solid state molecular behaviour together with intermolecular interactions have been deeply studied for this type of compounds. In collaborations with synthetic scientists we have developed novel Pt complexes able to produce, in the solid state, highly luminescent supramolecular species (dimers, excimers, aggregates). By carefully designing the device structure and the layers’ compositions we have prepared bright and efficient devices having emissions in different spectral regions.
(read more...)

Photoresponsive Materials for Sensing and Imaging

We investigate materials with optical properties (absorption, emission spectral features and lifetime) which can change in response to binding and/or recognition events and are useful for sensing and imaging applications. Focus of our research are molecules and nanostructures which show: i) turn-on fluorescence recognition mechanisms in the presence of toxic or critical metabolic ions ii) turn on fluorescence upon recognition of G-quadruplex structures of DNA and iii) turn on fluorescence upon intracellular delivery.
(read more...)

Photoactive Materials for Biomedical Applications

We investigate molecules that, upon interaction with light, generate useful chemical species and/or radicalic events and can be used as therapeutic agents. Our current research activity deals with: i) porphyrin and porphyrazin-based systems for photodynamic therapy and theranostic applications, and ii) naphthalene diimides as singlet oxygen sensitizers. We also explore different types of nanoparticles, some labelled with fluorophores, serving as carriers for singlet oxygen sensitizers and conventional drugs. Moreover, we synthesize RAFT controlled polymers to be also labelled with fluorescent probes. These polymers, that can be designed with self-assembling properties to form micelles, are studied as delivery and/or diagnostic agents.
(read more...)

Photoredox Catalysis

We tested the activity of two cyclometalated iridium(III) complexes as photocatalysts for radical Michael reactions, under very mild reaction conditions. Under visible light irradiation, differently substituted carboxylic acids undergo a photocatalytic oxidation, generating radicals capable of performing addition to a variety of Michael acceptors.
By tuning the excited-state oxidation potential of the photocatalysts, the selective formation of radicals only from α-heterosubstituted carboxylates can be obtained. This broad-scope reaction allows the formation of C–C bonds with high yields, under very mild reaction conditions, without the use of strong bases (Chem. Sci. 2017, 8, 1613-1620).
If the same kind of photocatalytic reaction is performed using zinc sulfinates as precursors of radical Michael donors, the hardly achievable benzylation of a variety of electron-poor olefins can be easily realized in good yields (ACS Catal. 2017, 7, 5357-5362).
(read more...)