Syntheses of novel oligothiophenes with highly polarizable extended π-electron systems that possess photoinduced intramolecular charge transfers at low energies. By proper choice of internal Donor-Acceptor architectures and by means of targeted syntheses it is possible to obtain valuable low bandgap donor materials to be used in organic photovoltaics.
Compared to conjugated polymers, small molecules can offer several intrinsic advantages in organic electronics applications. They possess well-defined chemical structures, and purity far higher with relatively simple low-cost syntheses and purification methods. Among small molecules for Organic Photovoltaics, thiophene oligomers possess extended π-electron delocalization along the backbone and are good hole-transporting materials. In general, dipolar push-pull chromophores with highly polarizable π-electron systems with donor (D) and acceptor (A) groups possess properties that result from the existence of photoinduced intramolecular charge transfers at quite low energies. The research deals with the syntheses of novel oligothiophene derivatives with different lengths (in terms of thiophene units), different solubilizing alkyl chains, different endcapping groups with different electron-accepting properties can help to control the tunability of the wavelength range of absorption, and several "core" architectures, in order to achieve the goals of better physico-chemical, optical and electrochemical properties as valuable low bandgap donor materials in Organic Solar Cells.
Electronic excitations in solution-processed oligothiophene small-molecules for organic solar cells. F. Gala, L. Mattiello, F. Brunetti, G. Zollo. Journal of Chemical Physics (2016, in press).
Leonardo Mattiello Dept. of Basic and Applied Sciences for Engineering - University of Rome "La Sapienza" Via del Castro Laurenziano 7 - 00161 Rome Italy email: leonardo.mattiello@uniroma1.it - web: sbai.uniroma1.it/~leonardo.mattiello