Structural, electronic, and hyperfine properties of pure and Ta-dopedm-ZrO2

Abstract

A combination of experiments and ab initio quantum-mechanical calculations has been applied to examine electronic, structural, and hyperfine interactions in pure and Ta-doped zirconium dioxide in its monoclinic phase (m-ZrO 2 ). From the theoretical point of view, the full-potential linear augmented plane wave plus local orbital (APW + lo) method was applied to treat the electronic structure of the doped system including the atomic relaxations introduced by the impurities in the host in a fully self-consistent way using a supercell approach. Different charge states of the Ta impurity were considered in the study and its effects on the electronic, structural, and hyperfine properties are discussed. Our results suggest that two different charge states coexist in Ta-doped m-ZrO 2 . Further, ab initio calculations predict that depending on the impurity charge state, a sizeable magnetic moment can be induced at the Ta-probe site. This prediction is confirmed by a new analysis of experimental data.

Aqueous dye-sensitized solar cells

“…Moreover, with the aim of improving the photovoltage, Su and coworkers 178 coupled this system with a ZrO 2 photoanode characterised by a wide band gap energy (5.8 eV) and a CB higher than that of TiO 2 . 179,180 When the green part of Codiaeum varie (CV-G) was used, a V oc of 0.624 V was achieved, definitely higher than those usually measured for natural pigment-sensitized TiO 2 -based DSSCs. 181 Furthermore, the effective dielectric constant and refractive index of the ZrO 2 layer were experimentally tuned, and the light transmission of the photoanode was improved, resulting in a cell efficiency of 0.69% ( J sc = 0.52 mA cm À2 , FF = 0.53).…”

Different Radiation Tolerances of Ultrafine-Grained Zirconia–Magnesia Composite Ceramics with Different Grain Sizes

“…Radiation tolerance performance of the nanostructured material is size-dependent, according to the theory of kinetics and thermodynamics [10]. The ideal grain size for nanocrystals with “self-healing” behavior may be a delicate balance between the excess free energy from GB, the free energy of phase transition and defect formation, and the healing kinetics [11]. Since there are no available data for the ideal grain size of nanostructured ZrO 2 , it is worthy of further exploration for the purpose of avoiding these problems.…”

Performance enhancement of natural pigments on a high light transmission ZrO2nanoparticle layer in a water-based dye-sensitized solar cell

“…ZrO 2 has a wide band energy (~5.8 eV) [11], the conduction level of which is higher than that of TiO 2 [12], which has the potential to increase the V OC . The exact mix used to produce the ZrO 2 nanoparticle-air layer is an important factor in the resulting properties, and if the percentage can be directly and efficiently controlled, the layer can be tailored to the required conditions.…”

“…ZrO 2 nanoparticles are a promising material for use in green buildings because of their very low thermal conductivity and high refractive index. ZrO 2 has a wide band energy (~5.8 eV) [11], the conduction level of which is higher than that of TiO 2 [12], which has the potential to increase the V OC . Natural pigment is a type of simply prepared, environmentally friendly, and low cost photosensitizer.…”