Radiation‐Tolerant Properties of Mg 2 XN 3 (X = Nb, Sb) Nitrides: A First‐Principles Study Toward Ion Beam‐Driven Functional Applications

In this work, we report the optical properties of Mg- and Ni-doped Ag2S colloidal nanoparticles. The Mg- and Ni-doped Ag2S nanoparticles were prepared using a wet chemical method. The influence of doping on the optical properties of the Mg- and Ni-doped Ag2S nanoparticles was investigated. The transmission electron microscopy (TEM) images showed the shapes of particles to be spherical with an average particle size of about 5–18 nm for all pure and doped Ag2S nanoparticles. The absorption spectra of the Mg-doped samples were red shifted from 2.42 to 2.20 eV, however, the UV-vis spectra of the Ni-doped Ag2S showed a blue shift from 2.42 to 2.60 eV. The observed blue shift in the band gap of Ni-doped Ag2S may be due to the substitution of Ni in to the Ag2S lattice. The photoluminescence intensity of the Mg-doped Ag2S nanoparticles increased as the Mg concentration was increased. However, the photoluminescence (PL) intensity of the Ni-doped Ag2S decreased as the concentration of Ni was increased.

We have studied the structural, optical, electronic and electrical properties of pure and Mg doped ZnO nanosheets compared to bulk ZnO, using the Density Functional Theory (DFT) within the Full Potential Linearized Augmented Plane Wave (FP-LAPW) formalism. The calculated band structure, total and partial densities of states show that the ZnO nanosheet have a large band gap than the other found in the bulk ZnO, which increases with increasing concentration of Mg. The absorption coefficient and optical transmittance show a red-shift after doping ZnO, whereas, the reflectivity and electrical conductivity are reduced. These good optical properties of ZnO nanosheets make it promising in optoelectronic devices, especially in solar cell application.

Microstructural and optical properties of high-quality Mg–Zn oxide thin films

The optical properties of Mg(I) have been computed using a CI approach in which the multi-electron basis includes single and double excitations from the M shell plus single excitations from the Ne-like core. The orbital set is of type and comprises STO, hydrogenic plus spatial oscillating STOCOS functions. The continuum states have been obtained by solving a discretized integral equation for the K-matrix half on the energy shell. Oscillator strengths and radiative lifetimes for the discrete states of the , and manifolds have been computed together with one- and two-photon cross sections of the ground and the states evaluated in the LOPT approximation. The maximum energies reached were 0.005 au and 0.035 au below the 4s ionization threshold for one- and two-photon processes, respectively. All the quantities have been determined in both the velocity and the length gauge.

Research on electronic structure and optical properties of Mg doped Ga0.75Al0.25N

Structural and optical properties of Mg xZn 1− xO thin films grown by metal-organic chemical vapor deposition

First-Principles Calculations of the Electronic Structures and Optical Properties of Mg- and Sr-Doped $CaF_2$

Electronic and optical properties of Mg-, F-doped and Mg∖F-codoped M1-VO2 via hybrid density functional calculations

Mg doped p-type GaN nanowires are grown using chemical vapor deposition technique in vapor-liquid-solid (VLS) process. Morphological and structural studies confirm the VLS growth process of nanowires and wurtzite phase of GaN. We report the optical properties of Mg doped p-type GaN nanowires. Low temperature photoluminescence studies on as-grown and post-growth annealed samples reveal the successful incorporation of Mg dopants. The as-grwon and annealed samples show passivation and activation of Mg dopants, respectively, in GaN nanowires.

The optical properties of Mg(I) have been computed using a configuration-interaction (CI) approach in which the multielectron basis includes single and double excitations from the M shell plus single excitations from the Ne-like core. The orbital set is of type and comprises STO, hydrogenic plus spatial oscillating STOCOS functions. The continuum states have been obtained by solving a discretized integral equation for the K matrix half-on-the-energy shell. For the , , and manifolds we have computed the discrete and autoionizing levels of the 3s nl, 3p nl, 4s nl and 3d nl series, the last two lying beyond the 3p ionization threshold.

It is well known that optical properties of Mg–Ni–H films can be tuned by hydrogen uptake from Mg–Ni–H and upload into Mg–Ni systems. In this work we show that modulation of optical properties of Mg–Ni–H can take place as a result of thermal processing in air as well. When reactively sputter deposited semiconducting Mg–Ni–H films are annealed at temperatures of 200 °C–300 °C in air, gradual band gap change from 1.6 to 2.04 eV occurs followed by change in optical appearance, from brown, to orange and, subsequently, to yellow. We investigate this phenomenon using optical and structural characterization tools, and link the changes to an atomic rearrangement and a structure reordering of the [NiH4]4−complex. The films are x-ray amorphous up to 280 °C, where above this temperature an increase in crystallite size and establishing of long-range order lead to a formation of the cubic crystalline phase of Mg2NiH4. Also, the results suggest that even though annealing was conducted in air, no oxidation or other changes in chemical composition of the bulk of the film occurred. Therefore, the band gap of this semiconductor can be tuned permanently by heat treatment, in the range from 1.6 to 2 eV.

The effect of growth ambient on the structural and optical properties of Mg xZn 1− xO thin films

Influence of annealing temperature on the structural and optical properties of Mg–Al co-doped ZnO thin films prepared via sol–gel method

Optical properties of Mg, from UV to IR, using ellipsometry and reflectometry

Ternary nitride semiconductors with tunable electronic structure and charge transport properties have attracted increasing attention as optoelectronic materials. The recently discovered ternary MgTMN2 (TM=Ti,Zr,Hf) are predicted to be nondegenerate semiconductors with visible-range optical absorption onsets. In the present study, the electronic structure, elastic properties, optical absorption spectrum, and dynamic stability of the MgTMN2 system have been systematically studied by first-principles calculations based on the density functional theory. These compounds show semiconductor characteristics with a bandgap ranging from 1.0 to 1.5 eV predicted by the Heyd–Scuseria–Ernzerhof approach. Compared to the traditional semiconductors of Si and GaAs and III–V nitrides of GaN and AlN, these ternary nitrides have stronger resistance to external compression, shear strain, and deformation due to the larger elastic modulus. MgTiN2 shows a strong anisotropy characteristic along the xy plane and z axis, while for MgZrN2 and MgHfN2, a weak elastic anisotropy is predicted. The absorption regions of these compounds are mainly concentrated in the ultraviolet region, and MgTiN2 is more sensitive to visible light with respect to the other two compounds. The thermodynamic stability of MgTiN2, MgZrN2, and MgHfN2 is verified by the stable phonon dispersion relations. It is found that the most stable low Miller index surface is (110) for MgTiN2 and (100) for MgZrN2 and MgHfN2.