Design of novel materials for efficient solar energy conversion is critical to the development of green energy technology. In this work, we present a first-principles study on the design of nanostructures for solar energy harvesting on the basis of the density functional theory. We show that the indirect band structure of bulk silicon nitride is transferred to direct bandgap in nanowire. We fin...

Structure found in the optical conductivity for radiation polarized parallel and perpendicular to the c-axis of a single-crystal of Gd below the Curie temperature has been correlated with direct interband transitions as derived from the spin-polarized conduction bands with the inclusion of the spin-orbit interaction as a perturbation. Spin-flip transitions not allowed for in the eleclric dipole...

We discuss the thermoelectric properties of NaxCoO2 using the electronic structure, as determined in first principles calculations, and Boltzmann kinetic transport theory. The Fermi energy lies near the top of a manifold of Co t2g bands. These t2g bands are separated by a large gap from the higherlying eg states. Although the large crystal-field splitting implies substantial Co–O hybridization,...

Vanadium oxide (V2O5) is a material that can be fabricated as a thin film of only a few atomic layers thick during mechanical exfoliation due to the weak interlayer interactions, much like how graphene is created. During this project we looked at the band structure of both the bulk and mono-layered V2O5. We used computer software called ABINIT, which is installed on the high performance compute...

Highly crystalline and pure lithium metasilicate (Li2SiO3) and lithium disilicate (Li2Si2O5) nanomaterials were synthesized by hydrothermal method and characterized by PXRD technique. The changes in the morphology and particle size of the synthesized nanomaterials with reaction time were investigated using SEM technique. The UV-Vis and photoluminescence spectra of the compounds were studied. Th...

In this paper, a new structure is provided for the dispersion compensating photonic crystal fibers in order to broaden the chromatic dispersion and increase the dispersion compensating capability in a wide wavelength range. In the structure, putting a combination of circular holes and a star structure in the inner core clad causes the dispersion coefficient profile to be broadened, and addition...

We report a synthetic, spectroscopic and computational study of the polycyclic aromatic molecule pyracene, which contains aliphatic five-membered rings annealed to a naphthalene chromophore. An improved route to synthesize the compound is described. Gas-phase IR and solid-state Raman spectra agree with a ground-state D2h structure. The electronically excited S1 A(1)B3u state has been studied by...

Highly crystalline and pure lithium metasilicate (Li2SiO3) and lithium disilicate (Li2Si2O5) nanomaterials were synthesized by hydrothermal method and characterized by PXRD technique. The changes in the morphology and particle size of the synthesized nanomaterials with reaction time were investigated using SEM technique. The UV-Vis and photoluminescence spectra of the compounds were studied. Th...

Micro-Raman spectra of single-walled carbon nanotubes in the range of two-phonon 2D bands are investigated in detail. The fine structure of two-phonon 2D bands in the low-temperature Raman spectra of the mixture and individual single-walled carbon nanotubes is considered as the reflection of structure of their π-electron zones. The dispersion behavior of 2D band fine structure components in the...