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Abstract ZnO/HfO2:Eu nanocables were prepared by radio frequency sputtering with electrospun ZnO nanofibers as cores. The well-crystallized ZnO/HfO2:Eu nanocables showed a uniform intact core–shell structure, which consisted of a hexagonal ZnO core and a monoclinic HfO2 shell. The photoluminescence properties of the samples were characterized. A white-light band emission consisted of blue, green, and red emissions was observed in the nanocables. The blue and green emissions can be attributed to the zinc vacancy and oxygen vacancy defects in ZnO/HfO2:Eu nanocables, and the yellow–red emissions are derived from the inner 4f-shell transitions of corresponding Eu3+ ions in HfO2:Eu shells. Enhanced white-light emission was observed in the nanocables. The enhancement of the emission is ascribed to the structural changes after coaxial synthesis.

Lithium phosphorus oxynitride (LiPON) film with high ionic conductivity, low electronic conductivity and high transparency in UV-VIS range offers the possible applications as electrolyte for optical devices, e.g. electrochromic device. In this work, the optical properties of LiPON are investigated by means of variable-angle spectroscopic ellipsometry (VASE) and optical transmission spectra. LiPON thin films with composition of Li3.13PO1.69N1.39 and ionic conductivity of 4.9 × 10−6 S cm−1 at room temperature were prepared by RF magnetron sputtering. Optical constants have been derived on multiple samples with film thickness from 400 to 2000 nm in the energy range of 0.58-5.5 eV. The optical bandgap ( Eg) of LiPON film is shown to be 3.07 eV by a Tauc plot. It is found that when E < Eg the Urbach exponential decay of absorption is observed. The Urbach tail width at room temperature is estimated to be 0.361 eV for the LiPON film. [ABSTRACT FROM AUTHOR]

Lithium silicon phosphorus oxynitride (LiSiPON) thin films with different compositions have been prepared by RF magnetron sputtering in N2 by using three targets xLi2SiO3 · (1 − x) Li3PO4 with x = 0.1, 0.3, and 0.5. Compared with LiPON, the electrical properties of LiSiPON have been improved by introducing silicon. LiSiPON films deposited from the target 0.5Li2SiO3 · 0.5Li3PO4 yield the highest ionic conductivity of up to 9.7 × 10−6 S cm−1 with an activation energy of only 0.41 eV. The main mechanism for increasing ionic conductivity is the enhancement of carrier mobility. By DC polarization measurements the electronic partial conductivity was found at least seven orders of magnitude smaller than the ionic conductivity. Linear voltammetry results showed that the LiSiPON films are electrochemically stable in contact with stainless steel in the voltage range of 0-6 V. The substitution of silicon for phosphorus in the film evidenced from X-ray photoelectron spectroscopy analysis indicated silicon in the film will create more abundant cross-linking structures Si-O-P and (P, Si)-N < (P, Si), hence created more Li+ conducting paths which favored the higher mobility of lithium ions and larger ionic conductivity. The optical bandgap was found to decrease with increasing silicon content. We demonstrate that the prepared LiSiPON films with their larger ionic conductivity and low electronic conductivity may serve as an alternative to LiPON for applications in high energy density and high voltage lithium batteries. [ABSTRACT FROM AUTHOR]

In this paper, BiOI@(BiO)2CO3 facet coupling heterostructures were synthesized via exfoliation and ion exchange, and characterized by X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra and valence-band XPS spectra. With the reaction time increasing, more BiOI can be transformed to (BiO)2CO3, and BiOI@(BiO)2CO3 facet coupling heterostructures were obtained. The photocatalytic results showed that BiOI@(BiO)2CO3 displays much higher photocatalytic activity than BiOI and (BiO)2CO3 under visible-light. The photocatalytic mechanism study revealed that BiOI@(BiO)2CO3 has strong adsorption for RhB molecules due to the ultrathin nanosheets and higher BET, and displays better separation efficiency of photoinduced charge carriers and higher photocurrent due to the {001}/{001} facet coupling. [ABSTRACT FROM AUTHOR]

ZnO/HfO2:Eu nanocables were prepared by radio frequency sputtering with electrospun ZnO nanofibers as cores. The well-crystallized ZnO/HfO2:Eu nanocables showed a uniform intact core–shell structure, which consisted of a hexagonal ZnO core and a monoclinic HfO2 shell. The photoluminescence properties of the samples were characterized. A white-light band emission consisted of blue, green, and red emissions was observed in the nanocables. The blue and green emissions can be attributed to the zinc vacancy and oxygen vacancy defects in ZnO/HfO2:Eu nanocables, and the yellow–red emissions are derived from the inner 4f-shell transitions of corresponding Eu3+ ions in HfO2:Eu shells. Enhanced white-light emission was observed in the nanocables. The enhancement of the emission is ascribed to the structural changes after coaxial synthesis. [ABSTRACT FROM AUTHOR]