The analogy between electromagnetic wave propagation in multidimensionally periodic structures and electronwave propagation in real crystals has proven to be a fruitful one. Initial efforts were motivated by the prospect of a photonic band gap, a frequency band in three-dimensional dielectric structures in which electromagnetic waves are forbidden irrespective of the propagation direction in sp...

Doping impurity into ZnO is an effective and powerful technique to tailor structures enhance its optical properties. In this work, Zn1−xMgxO Zn1−x−yMgxByO nanoparticles (x = 0, 0.1, 0.2, 0.3, 0.4; y 0.02, 0.04) were synthesized via one-pot method. It shows that the Mg B dopants has great influence on crystallinity surface morphology of nanoparticles, without changing wurtzite structure ZnO. The...

The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...

In this paper, we have studied the strain, band-edge, and energy levels of cubic InGaAs quantum dots (QDs) surrounded by GaAs. It is shown that overall strain value is larger in InGaAs-GaAs interfaces, as well as in smaller QDs. Also, it is proved that conduction and valence band-edges and electron-hole levels are size dependent; larger QD sizes appeared to result in the lower recombination...

The electronic properties and self-interaction effects of Zn5 xCrxTe (with x= 0.03125 and 0.0625), using the local spin density Approximation with a Hubbard term to improve the description of the d-Cr orbitals, is presented. These materials have potential technological applications as half-metallic and intermediate band materials. For a sufficiently high density of Cr substituting the Zn atoms ...

Angular resolved photoemission spectroscopy in combination with ab initio calculations show that trace amounts of carbon doping of the Bi_{2}Se_{3} surface allows the controlled shift of the Dirac point within the bulk band gap. In contrast to expectation, no Rashba-split two-dimensional electron gas states appear. This unique electronic modification is related to surface structural modificatio...

Recently, searching large-bulk band gap topological insulator (TI) is under intensive study. Through k·P theory and first-principles calculations analysis on antimonene, we find that α-phase antimonene can be tuned to a 2D TI under an in-plane anisotropic strain and the magnitude of direct bulk band gap (SOC gap) depends on the strength of spin-orbit coupling (SOC) which is strain-dependent. As...

The photoluminescence (PL) and PL excitation (PLE) spectra of the isolated Zn vacancy sVZnd in ZnSe are measured under hydrostatic pressure to 50 kbar at 7 K. The PL band shifts with pressure, roughly 30% faster than the band gap. Compression decreases the Stokes shift, reflecting a reduction in the C3y lattice relaxation around the V 2 Zn site. Defect-molecule calculations show that this arise...

Soft x-ray photoemission spectroscopy measurements of Fermi-level positions within the band gap of clean, GaAs(100) surfaces demonstrate that photovoltaic charging produces a major shift in the apparent band bending at low (50-100 K) temperatures. These measurements confirm recent predictions of Hecht [M. H. Hecht, Phys. Rev. B 41, 7918 (1990)], based on restoring currents limited by carrier tr...