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...

Si/Si1-xGex axial heterostructured nanowires (hNW) are under investigation for downscaling of metaloxide-semiconductor field-effect transistors (MOSFETs). New architectures based on vertically aligned nanowires tunnel-FETs are promising candidates for reduced power dissipation and low voltage operation [1]. The axial growth of lattice mismatched heterostructures would allow band-gap engineering...

A diketopyrrolopyrrole (DPP) with fluorenone (FN) based low band gap alternating copolymer (PDPPT-alt-FN) has been synthesized via Suzuki coupling. PDPPT-alt-FN exhibits a deep HOMO level with a lower band gap. Fabricated organic thin film transistors using PDPPT-alt-FN as a channel semiconductor show p-channel behaviour with the highest hole mobility of 0.083 cm(2) V(-1) s(-1) measured in air.

The photoconductance of poiycrystaHine silicon films at photon energies smaller than the band gap has been measured as a function of intensity applying a 1.3 pm wavelength semiconductor laser. The observed photosignaI increases superlinearly at low intensities and saturates above about 1.5 W / em 2. This distinct nonlinearity is caused by a significant energy dependence of optical to thermal cr...

Based on a thermodynamic model for size-dependent melting temperature, the size-dependent band-gap of low dimensional semiconductor compounds is modeled without any adjustable parameter. The model predicts an increase of the band-gap of nanoparticles and nanowires for IIBVIB and IIIB-VB semiconductor compounds, with decreasing their size, which is supported by available experimental and other t...

In optics, when polychromatic light is filtered by an optical filter, the monochromaticity of the light can be improved. In this work, we reported that Ag dopant atoms could be used as an optical filter for nanosized Mn:ZnSe quantum dots (QDs). If no Ag doping, aqueous Mn:ZnSe QDs have low monochromaticity due to coexisting of strong ZnSe band gap emission, ZnSe trap emission, and Mn dopant emi...

We have studied the structural, electronic and vibrational properties of the clathrates Ba8Al16Ge30 and Ba8Al16Si30 using the local density approximation (LDA). The equilibrium structures that we have obtained for these materials show that the Si-containing compound Ba8Al16Si30 is energetically more stable than its Ge counterpart Ba8Al16Ge30 by −0.38 eV per atom. We also find that Ba8Al16Si30 i...

Electromagnetic Band Gap (EBG) structures are nonperiodic structures that show unique electromagnetic features, such as frequency band gap for surface waves and in-phase reflection coefficient for incident plane waves, which makes them desirable for low-profile antenna designs. A very innovative topic for antenna scientists and engineers are the applications of EBG structures in antenna designs...

Abstract: Polarization converters play an important role in antennas and radar. Electromagnetic band gap materials enable manufacture of polarization converters which are : low cost, low profile, light weight and have large bandwidth. In this paper mushroom-like electromagnetic band gap materials are considered for polarization converters. The theory is reviewed. A simple design procedure is de...