Small Molecules for Organic Photovoltaics
Leonardo MATTIELLO (Sapienza Università di Roma)
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 OPV, 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 Team works on 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.
