Improved photoanode structure based on anodic titania nanotube array covered by TiO2-NPs/nanographite composite layer for ETA-cells

Abstract

This work is devoted to the morphology and electrical properties optimization of flexible photoanodes based on anodic titanium oxide nanotubular arrays (TiO2-NTAs) for solar cells with extremely thin absorbing layer (ETA-cells) by TiO2-nanographite thin composite layer formation on the TiO2-NTAs surface. First, the carbon doped TiO2-NTAs were synthesized by annealing of the as-anodized TiO2-NTAs in argon without foreign carbonaceous precursor. The residual ethylene glycol absorbed on the nanotube wall during anodization serves as the carbon source and the C species are uniformly distributed along the entire nanotube to form the C-TiO2 NTAs. Further decorating of C-TiO2-NTAs surface by TiO2 nanoparticles to form the TiO2-nanographite (NG) composite layer with high conductivity and increased photoanode effective area showed improved ETA-cells performance.