This article is about the mobility for electrons and holes in metals and semiconductors. For the general concept, see Electrical mobility.
In solid-state physics, the electron mobility characterises how quickly an electron can move through a metal or semiconductor when pushed or pulled by an electric field. There is an analogous quantity for holes, called hole mobility. The term carrier mobility refers in general to both electron and hole mobility.
Electron and hole mobility are special cases of electrical mobility of charged particles in a fluid under an applied electric field.
When an electric field E is applied across a piece of material, the electrons respond by moving with an average velocity called the drift velocity, . Then the electron mobility μ is defined as
Electron mobility is almost always specified in units of cm2/(V⋅s). This is different from the SI unit of mobility, m2/(V⋅s). They are related by 1 m2/(V⋅s) = 104 cm2/(V⋅s).
Conductivity is proportional to the product of mobility and carrier concentration. For example, the same conductivity could come from a small number of electrons with high mobility for each, or a large number of electrons with a small mobility for each. For semiconductors, the behavior of transistors and other devices can be very different depending on whether there are many electrons with low mobility or few electrons with high mobility. Therefore mobility is a very important parameter for semiconductor materials. Almost always, higher mobility leads to better device performance, with other things equal.
Semiconductor mobility depends on the impurity concentrations (including donor and acceptor concentrations), defect concentration, temperature, and electron and hole concentrations. It also depends on the electric field, particularly at high fields when velocity saturation occurs. It can be determined by the Hall effect, or inferred from transistor behavior.
In solid-state physics, the electronmobility characterises how quickly an electron can move through a metal or semiconductor when pushed or pulled by...
the material's electronmobility, and E is the electric field. In the MKS system, drift velocity has units of m/s, electronmobility, m2/(V·s), and electric...
and the HEMTs (high-electron-mobility transistors, or HFETs), in which a two-dimensional electron gas with very high carrier mobility is used for charge...
InP. It has an energy band gap of 0.75 eV, an electron effective mass of 0.041 and an electronmobility close to 10,000 cm2·V−1·s−1 at room temperature...
limited time Electrical mobility, ability of charged particles to move through a medium Electronmobility, how quickly an electron can move through a metal...
attained at an electric field of 225 kV/cm. With this information, the electronmobility was calculated, thus providing data for the design of GaN devices...
level of a solid-state body is the thermodynamic work required to add one electron to the body. It is a thermodynamic quantity usually denoted by μ or EF...
effectively screen the charge of an electron, known as a phonon cloud. This lowers the electronmobility and increases the electron's effective mass. The general...
concepts such as electronmobility. For partial filling at the top of the valence band, it is helpful to introduce the concept of an electron hole. Although...
resulting current, is characterized by the mobility; for details, see electronmobility (for solids) or electrical mobility (for a more general discussion). See...
to a material, free electrons will drift slowly through the material as described by the electronmobility. For low-energy electrons, faster drift velocities...
disadvantages. For example, gallium arsenide (GaAs) has six times higher electronmobility than silicon, which allows faster operation; wider band gap, which...
the speed of light in vacuum. The electrons themselves move much more slowly. See drift velocity and electronmobility. The speed at which energy or signals...
temperature. Electronmobility of ZnO strongly varies with temperature and has a maximum of ~2000 cm2/(V·s) at 80 K. Data on hole mobility are scarce with...
of electrons through the transistors and thus better mobility, resulting in better chip performance and lower energy consumption. These electrons can...
Some have properties such as hardness, thermal conductivity and electronmobility that are superior to those of most naturally formed diamonds. Synthetic...
field-effect transistors (MESFETs) as the active device. More recently high-electron-mobility transistor (HEMTs), pseudomorphic HEMTs and heterojunction bipolar...
superior to those of silicon. It has a higher saturated electron velocity and higher electronmobility, allowing gallium arsenide transistors to function at...
how InSb appeared to have a small direct band gap and a very high electronmobility. InSb crystals have been grown by slow cooling from liquid melt at...
displays remarkable electronmobility at room temperature, with reported values in excess of 15000 cm2⋅V−1⋅s−1. Hole and electronmobilities were expected to...
Electrical mobility is the ability of charged particles (such as electrons or protons) to move through a medium in response to an electric field that...
temperature, electrons in noble gasses move about freely, limited only by collisions with the weakly interacting atoms. Their mobility, which depends...
_{\mathrm {h} }}}.} Here n is the electron concentration, p the hole concentration, μe the electronmobility, μh the hole mobility and e the elementary charge...
as one example, in the transistor channel, which enhances electronmobility (or hole mobility) and thereby conductivity through the channel. Another example...
1970s. The semiconductor gallium arsenide (GaAs) has a much higher electronmobility than silicon, so devices fabricated with this material can operate...
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