Related papers: Band Anticrossing in Dilute Germanium Carbides Usi…

The direct bandgap found in hexagonal germanium and some of its alloys with silicon allows for an optically active material within the group-IV semiconductor family with various potential technological applications. However, there remain…

Conduction and valence band states for the highly mismatched alloy (HMA) Ge:C are projected onto Ge crystal states, Ge vacancy states, and Ge/C atomic orbitals, revealing that substitutional carbon not only creates a direct bandgap, but the…

Using spectroscopic ellipsometry measurements on GaP$_{1-x}$Bi$_{x}$/GaP epitaxial layers up to $x = 3.7$% we observe a giant bowing of the direct band gap ($E_{g}^{\Gamma}$) and valence band spin-orbit splitting energy…

We present ab initio calculations of the electronic and optical properties of hexagonal SiGe alloys in the lonsdaleite structure. Lattice constants and electronic band structures in excellent agreement with experiment are obtained using…

We report the realization of a new multi-band-gap semiconductor. The highly mismatched alloy Zn1-yMnyOxTe1-x has been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities…

Germanium is a strong candidate as a laser source for silicon photonics. It is widely accepted that the band structure of germanium can be altered by tensile strain so as to reduce the energy difference between its direct and indirect band…

The natural and true band profiles at heterojunctions formed by hexagonal Si$_x$Ge$_{1-x}$ alloys are investigated by a variety of methods: density functional theory for atomic geometries, approximate quasiparticle treatments for electronic…

Lonsdaleite germanium has a direct band gap, but it is not an efficient light emitter due to the vanishing oscillator strength of electronic transitions at the fundamental gap. Transitions involving the second lowest conduction band are…

The optical conductivity $\sigma_{1}(\omega)$ of Eu$_{1-x}$Ca$_{x}$B$_{6}$ has been obtained from reflectivity and ellipsometry measurements for series of compositions, $0\leq x\leq 1$. The interband part of $\sigma_{1}(\omega) $ shifts…

We report the compositional dependence of the electronic band structure for a range of III-V alloys. Density functional theory with the PBE functional is insufficient to mimic the electronic gap energies at different symmetry points of the…

We demonstrate the crossover from indirect- to direct band gap in tensile-strained germanium by temperature-dependent photoluminescence. The samples are strained microbridges that enhance a biaxial strain of 0.16% up to 3.6% uniaxial…

Before assessing the suitability of a semiconductor for specific applications, the first question to ask is whether it possesses a direct or indirect band gap. This distinction is fundamental, as the operation of devices such as…

Effects of antidot lattices on electronic structures of graphene and hexagonal BN (h-BN) are investigated using the first principles method based on density functional theory. For graphene, we find that when the antidot lattice is along the…

Anion substitution with bismuth (Bi) in III-V semiconductors is an effective method for experimental engineering of the band gap Eg at low Bi concentrations, in particular in gallium arsenide (GaAs). The inverse Bi-concentration dependence…

Some III-V digital alloy avalanche photodiodes exhibit low excess noise. These alloys have low hole ionization coefficients due to presence of small 'minigaps', enhanced effective mass and large separation between light-hole and split-off…

Conventional semiconductors typically have bonding states near the valence band maximum (VBM) and antibonding states near the conduction band minimum (CBM). Semiconductors with the opposite electronic configuration, namely an antibonding…

Modification of graphene to open a robust gap in its electronic spectrum is essential for its use in field effect transistors and photochemistry applications. Inspired by recent experimental success in the preparation of homogeneous alloys…

A theoretical study of the band gap reduction under tensile stress is performed and validated through experimental measurements. First-principles calculations based on density functional theory (DFT) are performed for uniaxial stress…

Ga$_2$O$_3$ and (Al$_x$Ga$_{1-x}$)$_2$O$_3$ alloys are promising materials for solar-blind UV photodetectors and high-power transistors. Basic key parameters in the device design, such as band gap variation with alloy composition and band…

The electronic band structure of atomically thin semiconductors can be tuned by the application of a perpendicular electric field. The principle was demonstrated experimentally shortly after the discovery of graphene by opening a finite…