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.

Unraveling the Cooperative Mechanism of Visible-Light Absorption in Bulk N,Nb Codoped TiO2 Powders of Nanomaterials

“…[20][21] Such materials have received considerable attention also for the development of highly efficient photoanodes in dyesensitized solar cells showing a reduced recombination loss and increased electron injection. [22][23] The structural, electronic and defective properties of Nb-promoted TiO2 systems play a major role in determining their final photoactivity. Two mechanisms have been proposed to account for the charge compensation of Nb 5+ introduced in the TiO2 lattice.…”

Nanostructured TiO2 Doped with Nb as a Novel Support for PEMFC

“…Finally, in the case of the carbonaceous support in Pt/C, a broad band ca. 25 ∘ , attributed to the (002) plane of turbostratic carbon, is clearly evident in its XRD pattern. Further insight on the crystallographic nature of the Ptsupported catalysts is gained from their transmission electron diffraction patterns, which are shown also in Figure 3.…”

“…Figure 4 allows estimating qualitatively the fraction of Nb that has effectively replaced Ti within the nanocrystalline structure. According to the comparison made with previous work on Nb-doped TiO 2 , [25] the Nb mole fraction is in a range between 0.025 and 0.050. As a matter of fact, the XRD pattern is closely similar to that exhibited by TiO 2 doped with Nb 5.0 mol%.…”

Anomalous behavior of B1g mode in highly transparent anatase nano-crystalline Nb-doped Titanium Dioxide (NTO) thin films

“…Niobium doped Titanium Dioxide (NTO) is a material of current interest for its salient superior properties for potential applications 1 such as improved performance of gas sensors, 2,3 photocatalytic applications, [4][5][6] enhance the electron injection in solar cells, 7 and as alternative conductive electrode. 8,9 The realization of applications also depends on their crystal structure like anatase (tetragonal), rutile (tetragonal), and brookite (orthorhombic).…”