Abstract. Band structure and optical properties of defectChalcopyrite type semiconductor ZnIn2Te4 have been studied by TB-LMTO first principle technique. The optical absorption calculation suggest that ZnIn2Te4 is a direct-gap semiconductor having a band gap of 1.40 eV., which confirms the experimentally measured value. The calculated complex dielectric-function ǫ(E) = ǫ1(E)+ iǫ2(E) reveal dist...

The luminescence of semiconductor nanostructures is strongly dependent on their size, dimensions, morphology, composition, or defects, and their band emissions can be properly and selectively tailored through the rational manipulation of these parameters during material growth. Using spatially-resolved cathodoluminescence spectroscopy, monochromatic contrast maps and high-resolution transmissio...

Wide-band-gap semiconductors typically can be doped either n type or p type, but not both. Compensation by native point defects has often been invoked as the source of this difficulty. We examine the wide-band-gap semiconductor ZnSe with first-principles total-energy calculations, using a mixed-basis program for an accurate description of the material. Formation energies are calculated for all ...

in this paper, a photonic crystal waveguide with point defects and lattice constant perturbations of +5%, -5% are being investigated. firstly waveguide structures with constant and specific parameters are being studied and photonic band gap diagrams for te/tm modes are depicted; then pulse propagation in the frequencies available in the band gap are shown. after that, effects of parameters like...

Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, <0001> oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap semiconductor nanowires form natural laser cavities with diameters varying from 20 to 150 nanometers and lengths up to 10 micr...

Recent development advances have allowed silicon (Si) semiconductor technology to approach the theoretical limits of the Si material; however, power device requirements for many applications are at a point that the present Si-based power devices can not handle. The requirements include higher blocking voltages, switching frequencies, efficiency, and reliability. To overcome these limitations, n...