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.

A new composite structure of TiO2|ZnO:Ti|ZnO effective for improving charge separation and electron transport is demonstrated for solar energy applications. A prototype material of hybrid TiO2/ZnO hollow spheres is prepared by a hydrated‐salt assisted solvothermal (HAS) strategy. This material is applied as a photocatalyst and an anode material for dye‐sensitized solar cells (DSSCs). Enhanced solar energy utilization efficiencies can be observed.

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Highly surface-textured ZnO:Al (AZO) thin films have been fabricated at room temperature by a two-step magnetron sputtering process and using an oxygen-deficient ZnO target with small grain sizes. The as-deposited AZO films are composed of a highly oriented seed layer and a closely packed columnar overlayer with pyramidal growth fronts, supporting a two-step mechanism of crystallite nucleation and grain growth. The structural, optical, and electrical properties of the AZO films can be tuned by the deposition conditions. The optimal two-step AZO film with a maximum root-mean-square roughness of 40.2 nm reaches a very low square resistance of 0.66 Ω/sq (ρ = 1.32 × 10−4 Ω·cm) with an average transparency of 87.9% in the range of 400−1100 nm. The maximum haze factor of the as-deposited film is 60.7% at 360 nm, and the average haze factor is 14.8%. These properties are comparable to or exceed the reported values of surface-textured SnO2- and ZnO-based transparent conducting oxide films, making our films suitable for transparent electrode applications, especially in thin-film solar cells.

Doping structures of Ce(3+) into the refractory α-sialon crystal lattice have been examined via an atom-resolved Cs-corrected scanning transmission electron microscope. The location and coordination of the rare-earth ions are well-defined through direct observation in conjunction with structural modeling and image simulation. The stability and solubility of Ce(3+) ions could be remarkably enhanced via congregation into the planar defects formed by a 1/3 (210)-type lattice displacement along with an inversion operation. The formation of cylindrical chambers near the defects is believed to provide effective structural relaxation upon doping of large rare-earth ions into the interstices in their neighborhoods. The as-revealed structural information could be useful for understanding the luminescence properties of the promising rare-earth doped sialon materials.

Single-crystalline uniform Ta(2)O(5) nanowires are prepared by a novel synthetic route. The formation of the nanowires involves an oriented attachment process caused by the reduction of surface energy. The nanowires are successfully applied to photocatalytic H(2) evolution, contaminant degradation, and dye-sensitized solar cells (DSCs). The Ta(2)O(5)-based DSCs reveal a significant photovoltaic response, which has not been reported. As a photocatalyst, the Ta(2)O(5) nanowires possess high H(2) evolution efficiency under Xe lamp irradiation, nearly 27-fold higher than the commercial powders. A better performance of photocatalytic contaminant degradation is also observed. Such improvements are ascribed to better charge transport ability for the single-crystalline wire and a higher potential energy of the conduction band. This new synthetic approach using a water-soluble precursor provides a versatile way to prepare nanostructured metal oxides.

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