Giorgia Possamai

Solar cells based on poly(3-alkyl)thiophenes and [60]fullerene: a comparative study

Photovoltaic cells made, at ambient conditions, from blends of regioregular poly(3-alkylthiophenes) and soluble fullerene derivatives are compared. It is shown that the cell performance is affected by the length of the donor side-chain, as it occurs in devices based on pure polythiophenes. The highest value of power conversion efficiency (0.84%) were obtained by using poly(3-hexylthiophene) and a fullerene concentration of 33-40% by weight. We anticipate a significant further improvement in power conversion efficiency upon a mild thermal treatment of the cells.

Solar cells based on a fullerene–azothiophene dyad

A power conversion efficiency of 0.37%, under white light of 80 mW cm-2 intensity, was obtained when a fullerene-azothiophene dyad was used as the active layer of a photovoltaic cell.

A stabilization effect of [60]fullerene in donor–acceptor organic solar cells

In this paper we compare the behavior of solar cells based on pure regioregular poly(3-hexylthiophene) with those in which the same polymer is blended with a functionalized fullerene, under continuous illumination. We found that the decay of both photocurrent and photovoltage signals with time is substantially reduced when the blend is used.

A fullerene-azothiophene dyad for photovoltaics

Abstract A fullerene-azothiophene donor–acceptor dyad is proposed as a photoactive material for organic solar cells. The photophysical characteristics and the structural properties of films of the dyad are investigated with time-resolved EPR (TREPR) and X-ray diffraction measurements. Solar cells made from the dyad were fabricated and their photovoltaic performance evaluated in function of the active layer thickness.