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.
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 ...
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 unpaired electrons in the dangling bonds of the surface atoms interact with each other to form an electronic state with a narrow energy band, located somewhere within the band gap of the bulk material. For simplicity, the surface state band is assumed to be half-filled with its Fermi level located at the mid-gap energy of the bulk.
An ohmic contact is a non-rectifying electrical junction: a junction between two conductors that has a linear current–voltage (I–V) curve as with Ohm's law.Low-resistance ohmic contacts are used to allow charge to flow easily in both directions between the two conductors, without blocking due to rectification or excess power dissipation due to voltage thresholds.
This is very similar to a true 'gap', which is an energy range that contains no allowed states. Such gaps open up, for example, when electrons interact with the lattice. The pseudogap phenomenon is observed in a region of the phase diagram generic to cuprate high-temperature superconductors, existing in underdoped specimens at temperatures ...
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 ...
The Ingenuity Gap is a popular science book. [10] Homer-Dixon takes an inter-disciplinary approach connecting political science with sociology, economics, history, biology, and ecology. [ 11 ] [ 12 ] [ 13 ] The narrative is structured as a travelogue as the author travels to meet experts and construct his theory. [ 14 ]