Robust and aligned carbon nanotube/titania core/shell films for flexible tco-free photoelectrodes

Carbon nanotube (CNT)/semiconducting oxide hybrids are an ideal architecture for light-harvesting devices, in which the CNTs are expected to not only act as a scaffold but also provide fast transport paths for photogenerated charges in the oxide. However, the current potential of CNTs for charge transport is largely suppressed due to the nanotubes not being interconnected but isolated by the low conductive oxide coatings. Herein, a flexible and conductive CNT/TiO₂ core/shell heterostructure film is reported, with aligned and interconnected CNTs wrapped in a continuous TiO₂ coating. Without using additional transparent conducting oxide (TCO) substrates, this unique feature of the film boosts the incident photon-to-electron conversion efficiency to 32%, outperforming TiO₂ nanoparticle electrodes fabricated on TCO substrates. Moreover, the film shows high structural stability and can generate a stable photocurrent even after being bent hundreds of times. A flexible and conducting heterostructure film with aligned carbon nanotubes wrapped in a continuous TiO₂ coating is reported. Enhanced photoconversion efficiency is observed in the film compared with TiO₂ nanoparticle electrodes fabricated on transparent conducting oxide (TCO) films. The film shows high structural stability and can generate a stable photocurrent even after being bent hundreds of times.