Prototype of a scalable core–shell Cu2O/TiO2 solar cell

Titanium oxide (TiO2) nanotube membranes are synthesized via a two-step anodization method. The conductivity at the crystallized barrier layer is enhanced by NH4Cl treatment. This facilitates electrodeposition of Cu2O into TiO2 nanotubes, creating Cu2O/TiO2 p–n heterojunctions in the radial direction. The photovoltaic performances benefit from the increased junction interface as well as the efficient pathway for separated charges to transport through the one-dimensional channel. Such heterojunction system serves as a promising candidate for solid-state solar cell due to its scalability, abundancy, low cost and environmental friendly nature. In addition, this versatile process can be conducted on various materials with the potential applications in photovoltaics, supercapacitor, battery, catalyst, etc.