The effect of barrier layers on 2D electron effective mass in AlGaN/AlN/GaN heterostructures.

The Shubnikov de Haas (SdH) effect measurements have been performed to evaluate the influence of SiNpassivation, a spacer layer, and Si-doped barrier layer on the electronic transport parameters of two-dimensional (2D) electrons in AlGaN/AlN/GaN heterostructures under temperatures from 1.8 K to 40 K and at a magnetic field up to 11 T. The 2D electron effective mass (*), 2D carrier density (), the difference between Fermi level and subband energy levels (-), quantum lifetime () are determined by analyzing SdH oscillations.

Structural parameters and electronic properties of 2D carbon allotrope: Graphene with a kagome lattice structure.

In this paper, the electronic properties of a carbon allotrope, graphene with a kagome lattice structure, are investigated. Spin-polarized density functional theory (DFT) calculations with Grimme dispersion corrections were done. Bond lengths, electronic band structure, and projected density of states were calculated.

The Relationship Between the Surface Morphology and Chemical Composition of Gunshot Residue Particles.

In this study, chemical composition and morphology of gunshot residue (GSR) of 9 × 19 mm Parabellum-type MKE (Turkey)-brand ammunition were analyzed by scanning electron microscope and energy dispersive X-ray spectrometer. GSR samples were collected by "swab" technique from the shooter's right hand immediately after shooting. According to general principles of thermodynamics, it is likely that the structures will have a more regular (homogeneous) spherical form to minimize their surface area due to very high temperatures and pressures that occur during explosion.

Optical gain in 1.3-μm electrically driven dilute nitride VCSOAs.

We report the observation of room-temperature optical gain at 1.3 μm in electrically driven dilute nitride vertical cavity semiconductor optical amplifiers. The gain is calculated with respect to injected power for samples with and without a confinement aperture.

Electronic transport in n- and p-type modulation doped Ga(x)In(1-x)N(y)As(1-y)/ GaAs quantum wells.

We present a comprehensive study of longitudinal transport of two-dimensional (2D) carriers in n- and p-type modulation doped Ga(x)In(1-x)N(y)As(1-y) /GaAs quantum well structures. The Hall mobility and carrier density of electrons in the n-modulation doped quantum wells (QWs) decreases with increasing nitrogen composition. However, the mobility of the 2D holes in p-modulation doped wells is not influenced by nitrogen and it is significantly higher than that of 2D electrons in n-modulation doped material.