Search results
Results from the WOW.Com Content Network
In solid-state physics, metal-induced gap states are electron states that exist near the surface of a semiconductor due to the presence of a metal on the surface. They have energies that fall within the semiconductor's bandgap thus are forbidden in the bulk of the semiconductor.
The common anion rule guesses that, since the valence band is related to anionic states, materials with the same anions should have very small valence band offsets. [citation needed] Tersoff [5] proposed the presence of a dipole layer due to induced gap states, by analogy to the metal-induced gap states in a metal–semiconductor junction.
This model includes a dipole layer at the interface between the two semiconductors which arises from electron tunneling from the conduction band of one material into the gap of the other (analogous to metal-induced gap states). This model agrees well with systems where both materials are closely lattice matched [11] such as GaAs/AlGaAs.
The nature of these metal-induced gap states and their occupation by electrons tends to pin the center of the band gap to the Fermi level, an effect known as Fermi level pinning. Thus the heights of the Schottky barriers in metal–semiconductor contacts often show little dependence on the value of the semiconductor or metal work functions, in ...
The closer f is to 1, the higher chance this state is occupied. The closer f is to 0, the higher chance this state is empty. The location of μ within a material's band structure is important in determining the electrical behaviour of the material. In an insulator, μ lies within a large band gap, far away from any states that are able to carry ...
Fluorescence microscopy relies upon fluorescent compounds, or fluorophores, in order to image biological systems.Since fluorescence and phosphorescence are competitive methods of relaxation, a fluorophore that undergoes intersystem crossing to the triplet excited state no longer fluoresces and instead remains in the triplet excited state, which has a relatively long lifetime, before ...
A pseudogap can be seen with several different experimental methods. One of the first observations was in NMR measurements of YBa 2 Cu 3 O 6+x by H. Alloul et al. [7] and by specific heat measurements by Loram et al. [8] The pseudogap is also apparent in ARPES (Angle Resolved Photoemission Spectroscopy) and STM (Scanning tunneling microscope) data, which can measure the density of states of ...
The change in spin state usually involves interchange of low spin (LS) and high spin (HS) configuration. [2] Spin crossover is commonly observed with first row transition metal complexes with a d 4 through d 7 electron configuration in an octahedral ligand geometry. [1]