Thermally evaporated fullerene (C₇₀) to bridge the charge transport in between nanostructured zinc oxide and conjugated copolymer in hybrid solar cell

We have investigated the effect of incorporating thin fullerene (C₇₀) layer in between nanostructured ZnO and conjugated co-polymer PCDTBT (Poly [[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]) for photovoltaic device performance. The addition of the fullerene layer enhances the electron transfer at the heterojunction from polymer to the metal oxide. The reason for the enhanced performance is investigated and it is observed that the fullerene layer can improve charge transfer process thorough the reduction of the trap induced interfacial recombination. The fullerene introduction is also helping in effective charge transfer (CT) excitons dissociation and transport at the interface. Encouraging improvement of the device performance was observed with the incorporation of C70 in this kind of hybrid solar cells.