Daniele Franchi

Italian National Research Council | CNR · Institute of Chemistry of Organometallic Compounds ICCOM

The integration of photovoltaic technologies within agricultural settings, also known as agrivoltaics, is attracting increasing attention as a sustainable approach to ensure both clean energy and food supply. The success of this strategy relies on the development of innovative materials that can selectively convert specific wavelengths into energy...

Among the emerging photovoltaic (PV) technologies, Dye-Sensitized Solar Cells (DSSCs) appear especially interesting in view of their potential for unconventional PV applications. In particular, DSSCs have been proven to provide excellent performances under indoor illumination, opening the way to their use in the field of low-power devices, such as...

Climate change mitigation on a global scale will only be possible through the achievement of ambitious decarbonisation goals, requiring an energy transition that involves switching from fossil fuels to clean fuels such as hydrogen. The photocatalytic approach is one of the most studied methods for directly converting sunlight into hydrogen. In this...

Two novel organic sensitizers for Dye-Sensitized Solar Cells (DSSC), called TP1 and TP2, based on the electron-poor thieno[3,4-b]pyrazine (TPz) π-bridge and the electron-rich N,N-bis(4-(hexylthio)phenyl)aniline (TPA) were designed following two different approaches: the classical D-A-π-A design and a symmetric structure with double anchoring functi...

A straightforward synthetic protocol featuring direct C–H arylations as key steps has been optimized to prepare two benzo-2,1,3-thiadiazole (BTD)-based organic fluorophores. Their light absorption and emission properties, as well as their affinity with poly(methyl methacrylate) as the chosen polymer matrix, were found to be suitable for application...

Optical Antennas (OAs) based on Fluorescent Concentrators (FCs) promise a revolution in the deployment of Visible Light Communication (VLC) and Optical Wireless Communication (OWC), due to their inherent advantages over conventional receivers in terms of exceedingly larger field of view (FoV) and optical gain (OG). Whilst FC-based OAs have been dem...

A series of heteroleptic Cu(I) diimine complexes with different ancillary ligands and 6,6′-dimethyl-2,2′-bipyridine-4,4′-dibenzoic acid (dbda) as the anchoring ligand were self-assembled on TiO2 surfaces and used as dyes for dye-sensitized solar cells (DSSCs). The binding to the TiO2 surface was studied by hard X-ray photoelectron spectroscopy for...

Organic fluorophores have found broad application as emitters in luminescent solar concentrators (LSCs) for silicon photovoltaics. In particular, the preparation of organic conjugated systems with intense light-harvesting ability, emissions in the deep-red and NIR regions, and large Stokes shift values represent a very challenging undertaking. Here...

Organic Near‐Infrared luminophores have found broad application as functional materials, but the development of efficient NIR emitters is still a challenging goal. Here we report on a new class of thieno[3,4‐b]pyrazine‐based NIR emitting materials with Aggregation Induced Emission (AIE) properties. The dyes feature a donor–acceptor–donor (D−A−D) st...

The industrial transition to more-sustainable chemical manufacturing requires the development of a variety of high-performance heterogeneous catalysts. Recently, new classes of heterogeneous and recyclable catalysts that exploit visible-light activation have emerged in the field of organic synthesis. Among these systems, sensitized semiconductors o...

A new series of symmetrical organic dyes containing an indigo central core decorated with different electron donor groups have been prepared, starting from Tyrian Purple and using the Pd-catalyzed Stille-Migita coupling process. The effect of substituents on the spectroscopic properties of the dyes has been investigated theoretically and experiment...

Due to ligand scrambling, the synthesis and investigation of the properties of heteroleptic Cu(I) complexes can be a challenging task. In this work, we have studied the optical and electrochemical properties of a series of homoleptic complexes, such as [Cu(dbda)2]+, [Cu(dmp)2]+, [Cu(Br-dmp)2]+, [Cu(bcp)2]+, [Cu(dsbtmp)2]+, [Cu(biq)2]+, and [Cu(dap)...

Cross-coupling reactions have played a key role in producing numerous types of π-conjugated small molecules having appealing properties for practical applications in organic electronics, especially in the field of photovoltaics. The main advantages of such synthetic methodology are the compatibility with many types of functional groups and the flex...

The design, synthesis, and characterization of a new class of blue-colored thiophene-substituted Pechmann dyes are reported. Due to a distinguishing blue coloration and the capability to absorb light in one of the most photon-dense regions of the solar spectrum, such compounds are of great interest for application as photoactive materials in organi...

In this work, we present for the first time the synthesis and characterization of potential DSSC organic sensitizers whose cyanoacrylic acceptor/anchoring group was modified by replacement of oxygen with one or more sulfur atoms. Using known carboxylic acid dye DF15 as a reference, their TD‐DFT computational analysis indicated that oxygen‐sulfur su...

In this study, we report on the synthesis of new organic fluorophores containing either the benzo[1,2-d:4,5-d']bisthiazole or the dithieno[3,2-b:2',3'-d]silole heterocyclic unit, and on their application for the fabrication of luminescent solar concentrators (LSCs) made of poly(methyl methacrylate) (PMMA) thin films. In solution, the new compounds...

D-π-A dyes have received a special attention in the field of dye-sensitized solar cells (DSSCs). In this kind of molecules, the acceptor group (A) generally acts as an anchor, enabling the adsorption of the dye onto the metal oxide substrate (TiO2) and providing a good electron injection. The search for new anchors represents a critical factor for...

The cross-coupling reaction of organic electrophiles with organostannanes, traditionally known as the Stille reaction, has found renewed interest in the preparation of new organic materials such as conjugated polymers, organic semiconductors and photoactive molecules for use in organic photovoltaics. Moreover, a very recent field in which the Still...

The effect of ionic liquid electrolytes on back electron-transfer rates for dye-sensitized TiO2 thin films was investigated using microsecond–millisecond transient absorption. For D35/TiO2 and [Ru(dcb)3]²⁺/TiO2 in electrolytes based on 1-alkyl-3-methyl-imidazolium hexafluorophosphate, significantly slower back electron-transfer rates, compared to t...

Two new organic dye-sensitized solar cell (DSSC) sensitizers bearing regioisomeric carboxyl-N-methylpyridinium moieties were prepared and fully characterized. Based on TD-DFT calculations, they were anticipated to show a significantly red-shifted absorption spectrum compared to normal carboxypyridines and other regioisomeric pyridinium salts. Altho...

Three novel organic dyes (DF13A-C) carrying regioisomeric carboxypyridine anchoring groups were synthesized by means of a multistep synthetic sequence involving a Pd-catalyzed Stille coupling as the key step. The new compounds underwent full spectroscopic, electrochemical, and computational characterization, and their properties were compared with...