Improved‐Performance Dye‐Sensitized Solar Cells Using Nb‐Doped TiO₂ Electrodes: Efficient Electron Injection and Transfer

Abstract

Well‐crystallized Nb‐doped anatase TiO2 nanoparticles are prepared by a novel synthetic route and successfully used as the photoanode of dye‐sensitized solar cells (DSSCs). The homogenous distribution of Nb in the TiO2 lattice is confirmed by scanning transmission electron microscopy (STEM) elemental mapping and line‐scanning analyses. After Nb doping, the conductivity of the TiO2 powder increases, and its flat‐band potential (Vfb) has a positive shift. The energy‐conversion efficiency of a cell based on 5.0 mol% Nb‐doped TiO2 is significantly better, by about 18.2%, compared to that of a cell based on undoped TiO2. The as‐prepared Nb‐doped TiO2 material is proven in detail to be a better photoanode material than pure TiO2, and this new synthetic approach using a water‐soluble precursor provides a simple and versatile way to prepare excellent photoanode materials.

Niobium doped anatase TiO 2 as an effective anode material for sodium-ion batteries

“…3), as evidenced by the slight peak shi of the (200) reection towards lower angles. This noticeable increase in the a parameter has been reported in the literature, 26,27 where the doping level was higher (10% vs. 5% in this study). Nb doping has expanded the unit cell, as can be seen from Fig.…”

“…2. This noticeable increase in the a parameter has been reported in the literature 26,27 , where the doping level was higher (10 % vs. , which indicates that the Nb has been successfully incorporated into the crystal structure of TiO 2 .…”

Mesoporous niobium-doped titanium dioxide films from the assembly of crystalline nanoparticles: study on the relationship between the band structure, conductivity and charge storage mechanism

“…54,55 However, as for thin lms Nb doping shis the Fermi-energy closer to the conduction band edge improving the electronic conductivity. 42,54 The same behavior is observed for our Nb:TiO 2 mesoporous thin lms where a maximum in electrical conductivity is found at a doping level of about 5 at%. At higher doping levels the mesoporous Nb:TiO 2 thin lms also seem to exhibit a reduction of the ionization efficiency due to trapping of electrons at Ti 4+ as indicated by the XPS results, which hint for a small Ti 3+ content for the 5 at% Nb:TiO 2 and 10 at% Nb:TiO 2 samples.…”

The Synthesis of Nb-doped TiO2 Nanoparticles for Improved-Performance Dye Sensitized Solar Cells

“…Moreover, one excess electron in the Ti 3d orbital for each Nb 5+ substitution would raise the electron concentration, which improves the electron conductivity. The similar tendency of E g shift was also reported by Lü et al [8] and Kim et al [25] As seen, the band gap of 5 mol% sample is larger than that of 2 mol% sample. The reason could be the increase of structural defect when incorporating a relative large amount of Nb dopant in the lattice.…”