Nano tuned conducting polymer for plastic solar cell

Abstract

Nano technology coupled with the plastic electronics has boosted the research field of plastic solar cells. Usually semiconducting nanocrystals have higher electron affinityto be used as electron acceptors and the conjugated polymers act as electron donors with the preferable energy gap of leV-3eV. Presently, we have doped TiO2 nano particles (particle size < 100nm) acting asthe N type semiconductor onto P-type organic semiconductor Poly (3-hexyl thiophene-2,5-diyl)P3HT. Embedded nano particles form multi P-N junctionsinside the polymer matrix forming a mixed junction photoactive blend. P3HT is tuned by adding TiO2 nano particles at 3:1, 1:1 and 1:3 weight ratio in Bromo -Benzene (BB) as the solvent and the photoactive films are prepared on glass plates by solution cast method. The absorption curve gets broadened indicating the reduction in the band gap (energy difference between HOMO & LUMO). Among the samples, 1:3 composite has the broad spectral sensitivity for absorption and can be considered to be the best photoactive blend for constructing the solar cell. Absorption by the blend can be further enhanced by either dye sensitization or by exploiting plasmon resonance without increasing the thickness of the film. It is planned to construct the solar cell using optimized 1:3 blend.