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Abstract ZnO nanowire–CdO composite nanostructures were fabricated by a simple two-step process involving ammonia solution method and thermal evaporation. First, ZnO nanowires (NWs) were grown on Si substrate by aqueous ammonia solution method and then CdO was deposited on these ZnO NWs by thermal evaporation of cadmium chloride powder. The surface morphology and structure of the synthesized composite structures were analyzed by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The optical absorbance spectrum showed that ZnO NW–CdO composites can absorb light up to 550 nm. The photoluminescence spectrum of the composite structure does not show any CdO-related emission peak and also there was no band gap modification of ZnO due to CdO. The photocurrent measurements showed that ZnO NW–CdO composite structures have better photocurrent when compared with the bare ZnO NWs.

A novel heterostructure of CdS nanoparticles/WO3 nanowhiskers was synthesized using a simple two-step process; thermal evaporation and chemical bath deposition. First, WO3 nanowhiskers (NWs) were grown on a tungsten substrate by thermal evaporation of WO3 powder in a tube furnace at 1050 °C. Sequentially, CdS nanoparticles (NPs) were deposited on WO3 nanowhiskers by chemical bath deposition. CdS nanoparticles modified WO3 nanowhiskers showed enhanced visible light absorption compared to bare WO3 nanowhiskers. The photocatalytic activity was studied by the photodegradation of methylene blue. CdS NP/WO3 NW heterostructures showed remarkably enhanced photodecomposition efficiencies compared to bare WO3 nanowhiskers. [ABSTRACT FROM AUTHOR]

Plasma-enhanced atomic layer deposition (PE-ALCVD) of ZrO2 was performed to coat SiC nanowires and prepare a SiC-ZrO2 core-shell nanowire structure. Zirconium tertiary butoxide (ZTB) and hydrogen plasma pulse cycles were used to grow ZrO2 films. The growth temperature of ZrO2 PE-ALCVD was 150°C with a growth rate of 1.3 Å/cycle. SEM and TEM images showed uniform coating of SiC nanowires with ZrO2. The thickness of ZrO2 coat layer could be controlled by the total number of the pulse cycles. After being annealed at 900°C, a polycrystalline structure of ZrO2 layer was observed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Correlations between carrier dynamics and structural defects of InGaN MQWs exist. [•] PL intensity is much weaker in the V-shaped pits than in the regular c-plane. [•] Blue-shifted photoluminescence spectrum is not observed at the V-pits. [•] A kinetic model including carriers recombination and diffusion is presented. [•] The model estimates the nonradiative recombination time as 10ps at the V-pits. [ABSTRACT FROM AUTHOR]

A simple, direct synthesis method was used to grow core-shell SiC-SiO(2) nanowires by heating NiO-catalysed silicon substrates. A carbothermal reduction of WO(3) provided a reductive environment and carbon source to synthesize crystalline SiC nanowires covered with SiO(2) sheaths at the growth temperature of 1000-1100 °C. Transmission electron microscopy showed that the SiC core was 15-25 nm in diameter and the SiO(2) shell layer was an average of 20 nm in thickness. The thickness of the SiO(2) shell layer could be controlled using hydrofluoric acid (HF) etching. Field emission results of core-shell SiC-SiO(2) and bare SiC nanowires showed that the SiC nanowires coated with an optimum SiO(2) thickness (10 nm) have a higher field emission current than the bare SiC nanowires.