Two types of thin-film infrared-sensing devices have been investigated using the narrow band-gap semiconductor, rhenium disilicide ~Eg;0.1 eV!. These are the ReSi2/n-Si heterojunction internal photoemission ~HIP! detector and the ReSi2 thin-film photoconductor. The HIP device was found to be rectifying and to obey a Fowler-type law with a long-wavelength cutoff of ;2.1 mm ~0.59 eV! at room temp...

Indium antimonide (InSb), a narrow band gap III-V semiconductor is a promising infrared-active material for various optoelectronic applications. Synthetic challenge of colloidal InSb nanocrystals (NCs) lies in the limited choice of precursors. Only a few successful synthetic schemes involving highly toxic stibine (SbH3) or air- and moisture-sensitive metal silylamides (In[N(Si-(Me)3)2]3 or Sb[N...

Using an ab initio local density approximation ~LDA! method, we have studied the structural properties and the electronic band structures of several tin-based clathrate materials. We find that the pure type-I (Sn46) and type-II (Sn136) clathrate frameworks are metastable, expanded-volume phases of Sn and that they are semiconductors. We further find that the Cs encapsulated type-I binary clathr...

We investigate the band-gap modiication by collapsing deformation in C, BN, and BC3 nanotubes through rst-principles pseudopotential calculations. Semiconductor-metal transitions occur when zigzag C and armchair BC3 nanotubes undergo collapsing deformation, while in zigzag BN tubes, a variation of band gaps from 5 to 2 eV is found. On the other hand, the band gaps of armchair BN and zigzag BC3 ...

It has been known for over twenty years that rhombohedral c-germanium telluride is predicted to be a narrow gap semiconductor. However, it always displays p-type metallic conduction. This behaviour is also observed in other chalcogenide materials, including Ge2Sb2Te5, commonly used for optically and electrically switched, non-volatile memory, and so is of great interest. We present a theoretica...

We demonstrate that DFT calculations performed with the local density approximation (LDA) allow for significantly better reproduction of lattice constants, the unit cell volume and the density of Ag(II)SO(4) than those done with generalized gradient approximation (GGA). The LDA+U scheme, which accounts for electronic correlation effects, enables the accurate prediction of the magnetic superexch...

optical modeling was applied for obtaining absorbance spectra and band gap values for different morphology of zno semiconductor. in optical modeling, the relative permittivity scalars of zinc oxide coral like nanorods were calculated using the bruggeman homogenization formalism. zno nano rods (zonrs) as a nucleus layer were fabricated on the indium tin oxide (ito) by chronoamperometry (ca) in a...

Single- and few-layer crystals of exfoliated MoTe2 have been characterized spectroscopically by photoluminescence, Raman scattering, and optical absorption measurements. We find that MoTe2 in the monolayer limit displays strong photoluminescence. On the basis of complementary optical absorption results, we conclude that monolayer MoTe2 is a direct-gap semiconductor with an optical band gap of 1...