It has been well-established that single layer MX2 (M = Mo, W and X = S, Se) are direct gap semiconductors with band edges coinciding at the K point in contrast to their indirect gap multilayer counterparts. In few-layer MX2, there are two valleys along the Γ-K line with similar energy. There is little understanding on which of the two valleys forms the conduction band minimum (CBM) in this thi...

We present the electronic band structures and dielectric tensors for a series of crystalline linear oligoacenes—i.e., naphthalene, anthracene, tetracene, and pentacene—calculated within the density functional framework. The band dispersions, the effective charge carrier masses, and the optical response are discussed as a function of the oligomer length compared to previously reported calculatio...

Femtosecond X-ray irradiation of solids excites energetic photoelectrons that thermalize on a timescale of a few hundred femtoseconds. The thermalized electrons exchange energy with the lattice and heat it up. Experiments with X-ray free-electron lasers have unveiled so far the details of the electronic thermalization. In this work we show that the data on transient optical reflectivity measure...

The band gap of semiconductors like silicon and silicon carbide (SiC) is the key for their device properties. In this research, the band gap of 6H-SiC and its temperature dependence were analyzed with silicon 2p x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and resonant inelastic x-ray scattering (RIXS) allowing for a separate analysis of the conduction-band minimum (CB...

The strong coupling of THz radiation and material excitations can improve the quantum efficiency of THz emitters. In this paper, we investigate THz polaritons and antipolaritons based on valence band transitions, which allow TE coupling in a simple configuration. The approach can improve the quantum efficiency of THz based devices based on TE mode in the strong coupling regime of THz radiations...

In this paper, we have presented a heterojunction gate all around nanowiretunneling field effect transistor (GAA NW TFET) and have explained its characteristicsin details. The proposed device has been structured using Germanium for source regionand Silicon for channel and drain regions. Kane's band-to-band tunneling model hasbeen used to account for the amount of band-to...