Search results
Results From The WOW.Com Content Network
X-ray absorption near edge structure (XANES), also known as near edge X-ray absorption fine structure (NEXAFS), is a type of absorption spectroscopy that indicates the features in the X-ray absorption spectra of condensed matter due to the photoabsorption cross section for electronic transitions from an atomic core level to final states in the energy region of 50–100 eV above the selected ...
X-ray absorption spectroscopy. X-ray absorption spectroscopy (XAS) is a widely used technique for determining the local geometric and/or electronic structure of matter. [1] The experiment is usually performed at synchrotron radiation facilities, which provide intense and tunable X-ray beams. Samples can be in the gas phase, solutions, or solids.
In semiconductors and insulators the two bands are separated by a band gap, while in conductors the bands overlap. A band gap is an energy range in a solid where no electron states can exist due to the quantization of energy. Within the concept of bands, the energy gap between the valence band and the conduction band is the band gap.
The Urbach Energy, or Urbach Edge, is a parameter typically denoted , with dimensions of energy, used to quantify energetic disorder in the band edges of a semiconductor. It is evaluated by fitting the absorption coefficient as a function of energy to an exponential function. It is often used to describe electron transport in structurally ...
Definition. An edge city is a term coined by Joel Garreau's in his 1991 book Edge City: Life on the New Frontier, for a place in a metropolitan area, outside cities' original downtowns (thus, in the suburbs or, if within the city limits of the central city, an area of suburban density), with a large concentration of jobs, office space, and retail space.
The conduction band (CB), edge states (ES) and valence band (VB) are characterized by positive, zero and negative energy eigenvalues. In solid-state physics, quantum mechanics, materials science, physical chemistry and other several disciplines we study the electronic band structure of materials primarily based on the extent of the band gap ...
K-edge. In X-ray absorption spectroscopy, the K-edge is a sudden increase in x-ray absorption occurring when the energy of the X-rays is just above the binding energy of the innermost electron shell of the atoms interacting with the photons. The term is based on X-ray notation, where the innermost electron shell is known as the K-shell.
Anderson's rule. Band diagrams for a straddling-gap type heterojunction, as understood by Anderson's rule. The junction alignment at equilibrium (bottom) is predicted based on a hypothetical flat-vacuum alignment (top). Anderson's rule is used for the construction of energy band diagrams of the heterojunction between two semiconductor materials.