Effect Of Selenium Doping Research Articles

Effect of Selenium Doping on the Electronic Properties of β-Ga2O3 by First-Principles Calculations

Effect of Selenium Doping on the Electronic Properties of β-Ga2O3 by First-Principles Calculations

Effects of Selenium Doping in Zinc Telluride from First Principles

Point defects and compensation in zinc telluride have been subjects of study for several decades due to the compound’s scientific/technological applications. Despite this, there remains some disagreement in the literature as to the fine details of its defect chemistry. Recently, it has also come under renewed interest due to the emerging Cd(1–x)ZnxTe(1–y)Sey material family, used in nuclear radiation detector applications. In this article, we use state-of-the-art computational tools to re-examine the native defect chemistry of ZnTe and explore how it changes upon addition of selenium using density functional theory with screened hybrid exchange–correlation functionals, thermochemical models of the equilibration environment, and statistical mechanics models of the point defect ensemble.

Effect of selenium doping on the crystallization behaviors of GeSb for phase-change memory applications

We investigated the effect of Se doping on the physical and electrical properties of Ge10Sb90 films prepared by sputtering. We examined the crystal structure, chemical bonding, electrical and thermal properties, and volume shrinkage during the crystallization of Ge10Sb90 films doped concentrations of Se between 0 and 20 at.%. X-ray diffraction patterns showed that incorporating Se leads to phase separation at high Se concentrations. As the Se concentration increased, both the crystallization temperature (Tc) and the sheet resistance increased in both the amorphous and crystalline states. In contrast, the melting temperature (Tm) and grain size both decreased with the increasing Se. The volume shrinkage of the Se-doped Ge10Sb90 films was analyzed by X-ray reflectivity measurements. Our results demonstrate that Se-doped Ge10Sb90 films show a favorably low operation current and good thermal and mechanical stability, which strongly indicate their feasibility for phase-change memory applications.

Effect of selenium doping on structural and optical properties of SnS:Se thin films by electron beam evaporation method

SnS nanoparticle has been synthesized initially using SnCl 2 · 2H 2 O and Na 2 S · XH 2 O, in the presence of TEA by precipitation method and XRD and FTIR techniques have been used for characterization of the sample. Powder X-ray diffraction studies revealed the particle size to be 48 nm and the pattern represents polycrystalline herzenbergite orthorhombic crystal structure of SnS. The FTIR result also confirmed the SnS at 2354 cm − 1 . Secondly SnS:Se thin films have been deposited on glass substrates by electron beam evaporation technique and the films were annealed at 100 °C and 200 °C for 1 h. The unannealed films are amorphous in nature and the annealed film shows that a sharp crystalline peak is due to SnS. Also a peak is shown at 2 θ = 14.39°, which is due to characteristic peak of SnSe 2 , established by their XRD patterns. The band gap energy ( E g ) was determined from transmission spectra and an optical band gap of E g varies from 1.6 eV to 1.79 eV.

Materials based on bismuth and antimony chalcogenides for thermoelectric cooler stages

To enhance the efficiency of multistage thermoelectric coolers, extruded materials based on p- and n-type solid solutions of bismuth and antimony chalcogenides have been optimized for particular temperatures in the range 100–300 K. We have studied the effect of selenium doping on the thermoelectric efficiency of the p-type materials. We have fabricated pilot micromodules and compared calculated and experimentally determined characteristics (maximum temperature difference and thermoelectric figure of merit) of the modules in the range 100–300 K.

Effect of Selenium Doping on Corrosion and Electrochemical Performance of Pb-Sb-As-Se Alloys as Positive Grids in Hybrid Lead-Acid Batteries

Effect of Selenium Doping on Corrosion and Electrochemical Performance of Pb-Sb-As-Se Alloys as Positive Grids in Hybrid Lead-Acid Batteries

Effect of selenium doping on superconductivity in high-pressure synthesis T′ structure Sm 1.85Ce 0.15CuO 4

Selenium doped Sm 1.85Ce 0.15CuO 4 was prepared at a high-temperature/high-pressure condition. The magnitudes of resistivity are decreased with increasing Se concentration in the samples. The superconductor was obtained at Se concentration x = 0.3 and required no additional reducing treating. We propose that selenium doping maybe produce SeO 2 under high-pressure and provide a weak reducing environment to trigger superconducting. Result of XPS and XRD measurements on the sample supports this model.

The effect of selenium doping on the optical and structural properties of Ga0.5ln0.5P

Selenium doping at an electron concentration of 1018 – 1019 cm−3 is shown to cause an increase in both the band gap and the disorder of Ga0.5In0.5P films grown by metalorganic chemical vapor deposition on GaAs substrates. The effect of selenium is shown to be very similar to that of the p-type dopants, zinc and magnesium. Selenium doping is also shown to have a dramatic smoothing effect on the surface morphology of Ga0.5In0.5P films.

Transmission electron microscopy study of the effect of selenium doping on the ordering of GalnP2

Selenium doped Ga0.51In0.49P films have been grown by metalorganic chemical vapour deposition at 600, 670 and 740° C. The extent of ordering of the Group III sublattice has been monitored by transmission electron microscopy. Ordering disappears at carrier concentrations on the order of 1018 cm−3 for samples grown at 600 and 740° C although a small degree of ordering persists in the samples grown at 670° C up to a carrier concentration of 1019 cm−3. At each growth temperature, the ordering observed decreased and the bandgap measured increased with increasing Se doping.