Plasmonic, interior-decorated, one-dimensional hierarchical nanotubes for high-efficiency, solid-state, dye-sensitized solar cells

Abstract

We report a high energy conversion efficiency of 8.4% at 100 mW cm⁻², which is one of the highest values for N719-based, solid-state, dye-sensitized solar cells (ssDSSCs). Our solar cells are based on one-dimensional (1D) hierarchical hetero-nanotubes consisting of Au cores and SnO₂/TiO₂ nanosheet double shells (referred to as Au@SnO₂@TNSs). Carbonaceous nanofibers (CNFs) with tellurium (Te) cores are used as dual templates for the inner-deposition of gold and the outer-deposition of the metal oxide layers. An organized mesoporous TiO₂ (OM-T) film, with high porosity, large pores, and good interconnectivity, is also prepared via a graft copolymer template approach and utilized as a matrix to disperse the 1D hierarchical nanostructures. Such nanostructures provide good pore-filling for solid electrolytes, faster electron transfer, and enhanced light scattering, as confirmed by reflectance spectroscopy, incident photon-to-electron conversion efficiency (IPCE) spectroscopy, and intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS).