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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 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 ...
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.
It was noted in 1947 by John Bardeen that the Fermi level pinning phenomenon would naturally arise if there were chargeable states in the semiconductor right at the interface, with energies inside the semiconductor's gap. These would either be induced during the direct chemical bonding of the metal and semiconductor (metal-induced gap states ...
Band bending can be induced by several types of contact. In this section metal-semiconductor contact, surface state, applied bias and adsorption induced band bending are discussed. Figure 1: Energy band diagrams of the surface contact between metals and n-type semiconductors.
When it comes to men and women having orgasms during sex, there is a gap that’s hard to ignore. According to a 2017 study published by the Archives of Sexual Behavior, 95% of heterosexual men ...
The band gap is called "direct" if the crystal momentum of electrons and holes is the same in both the conduction band and the valence band; an electron can directly emit a photon. In an "indirect" gap, a photon cannot be emitted because the electron must pass through an intermediate state and transfer momentum to the crystal lattice.
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 ...