Peptide-templating dye-sensitized solar cells

A hollow TiO₂ nanoribbon network electrode for dye-sensitized solar cells (DSSC) was fabricated by a biotemplating process combining peptide self-assembly and atomic layer deposition (ALD). An aromatic peptide of diphenylalanine was assembled into a three-dimensional network consisting of highly entangled nanoribbons. A thin TiO₂ layer was deposited at the surface of the peptide template via the ALD process. After the pyrolysis of the peptide template, a highly entangled nanotubular TiO₂ framework was successfully prepared. Evolution of the crystal phase and crystallite size of the TiO₂ nanostructure was exploited by controlling the calcination temperature. Finally, the hollow TiO₂ nanoribbon network electrode was integrated into DSSC devices and their photochemical performances were investigated. Hollow TiO₂ nanoribbon-based DSSCs exhibited a power conversion efficiency of 3.8%, which is comparable to the conventional TiO ₂ nanoparticle-based DSSCs (3.5%). Our approach offers a novel pathway for DSSCs consisting of TiO₂ electrodes via biotemplating.