Hyperbranched Quasi-1D TiO2 Nanostructure for Hybrid Organic–Inorganic Solar Cells
journal contributionposted on 15.04.2015, 00:00 authored by Ali Ghadirzadeh, Luca Passoni, Giulia Grancini, Giancarlo Terraneo, Andrea Li Bassi, Annamaria Petrozza, Fabio Di Fonzo
The performance of hybrid solar cells is strongly affected by the device morphology. In this work, we demonstrate a poly(3-hexylthiophene-2,5-diyl)/TiO2 hybrid solar cell where the TiO2 photoanode comprises an array of tree-like hyperbranched quasi-1D nanostructures self-assembled from the gas phase. This advanced architecture enables us to increase the power conversion efficiency to over 1%, doubling the efficiency with respect to state of the art devices employing standard mesoporous titania photoanodes. This improvement is attributed to several peculiar features of this array of nanostructures: high interfacial area; increased optical density thanks to the enhanced light scattering; and enhanced crystallization of poly(3-hexylthiophene-2,5-diyl) inside the quasi-1D nanostructure.