Characteristics of undoped and Sb-doped ZnO thin films prepared in different atmospheres by pulsed laser deposition
Growth and annealing of zinc-blende CdSe thin films on GaAs (001) by molecular beam epitaxy
CdSe thin films have been grown on GaAs (0 0 1) substrates by molecular beam epitaxy (MBE). The effects of substrate temperature and annealing treatment on the structural properties of CdSe layers were investigated. The growth rate slightly decreases due to the accelerated desorption of Cd from CdSe surface with an increase in the temperature. The ...
Thermal characteristic of GaAs-based laser diodes
In order to analyze the thermal characteristic of GaAs-based laser diodes during degradation, aging tests were carried out under the conditions of the constant current stress for808 nm GaAs-based laser diodes. The temperature of active layer and the thermal resistance were investigated by using electrical method. It was found that the temperature o...
Effects of grain size on resistance and transmittance transition of vanadium oxide thin film
Vanadium oxide thin films were deposited by reactive direct current facing targets magnetron sputtering, and then annealed in oxygen ambience under different temperature to fabricate phase transition vanadium dioxide thin films with different grain size. The transformation of resistance and transmittance of vanadium oxide thin films were measured a...
ZnO-Bi2O3-based varistor ceramics prepared by direct high-energy ball milling of the dopants
The microstructure and electrical properties of ZnO-Bi2O3-based varistor ceramics prepared by direct high-energy ball milling of the dopants were studied. The varistor ceramics samples were characterized by XRD and SEM analysis, as well as by dc electrical measurements, such as the nonlinearity coefficients, leakage current and threshold voltage. T...
Low temperature annealing effects on the structure and optical properties of ZnO films grown by pulsed laser deposition
ZnO thin films were deposited on glass substrates at room temperature (RT) similar to 500 degrees C by pulsed laser deposition (PLD) technique and then were annealed at 150-450 degrees C in air. The effects of annealing temperature on the microstructure and optical properties of the thin films deposited at each substrate temperature were investigat...
First-principles prediction of the magnetism of 3d transition-metal-doped Rocksalt MgO
Using first-principles band structure methods, we have systematically studied the electronic structures, magnetic stabilities, and half-metal properties of 3d transition-metal (TM) doped Rocksalt MgO compounds TMMg3O4 (TM = V, Cr, Mn, Fe, Co, and Ni). The calculations reveal that only CrMg3O4 has a ferromagnetic stability among the six compounds, w...
Photoluminescence spectroscopy and positron annihilation spectroscopy probe of alloying and annealing effects in nonpola...
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Temperature-dependent photoluminescence characteristics of non-polar m-plane ZnO and ZnMgO alloy films grown by metal organic chemical vapor deposition have been studied. The enhancement in emission intensity caused by localized excitons in m-plane ZnMgO alloy films was directly observed and it can be further improved after annealing in nitrogen. T...
Optical properties of aluminum-, gallium-, and indium-doped Bi4Ti3O12 thin films
Undoped and Al-, Ga-, and In-doped Bi4Ti3O12 thin films were prepared on fused quartz substrates by chemical solution deposition. Their microstructures and optical properties were investigated by x-ray diffraction and UV-visible-NIR spectrophotometer, respectively. The optical band-gap energies, Urbach energies, and linear refractive indices of all...
Enhancement of conductivity and transmittance of ZnO films by post hydrogen plasma treatment
We studied the effects of hydrogen plasma treatment on the electrical and optical properties of ZnO films deposited by radio frequency magnetron sputtering. It is found that the ZnO H film is highly transparent with the average transmittance of 92% in the visible range. Both carrier concentration and mobility are increased after hydrogen plasma tre...
