"The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body."
The energy level in a solid at which electrons have a 50% probability of being occupied.
Energy bands: Energy bands in materials describe how electrons are allowed to occupy specific energy states. These energy states have different probabilities of being occupied by electrons and these probabilities determine the electrical conductivity and other material properties.
Zone scheme: The zone scheme is a way to organize energy bands in materials by their momentum in the crystal lattice. The different zones correspond to different arrangements of atoms in the crystal lattice and their corresponding energy states.
Density of states: The density of states is a measure of the number of energy states per unit volume per unit energy interval. The number of available states at a given energy is crucial in determining the behavior of electrons in a material.
Fermi-Dirac distribution: The Fermi-Dirac distribution function is used to calculate the probability of electrons occupying a given energy state. It describes the distribution of particles (electrons) in a non-interacting system at thermal equilibrium.
Fermi level: The Fermi level is the energy level at which the probability of finding an electron is exactly 50%. It is named after Enrico Fermi, an Italian physicist who developed the idea of the Fermi-Dirac distribution.
Doping: Doping is a process of adding impurities to a material in order to modify its properties. This can be used to manipulate the Fermi level and alter electrical conductivity.
Carrier concentration: Carrier concentration is the number of mobile charge carriers (electrons or holes) in a material. It is determined by the concentration of donors and acceptors, the temperature, and the Fermi level.
Carrier mobility: Carrier mobility is a measure of how easily electrons or holes move through a material. It is affected by temperature, doping, and defects in the material.
Bandgap engineering: Bandgap engineering is a process of modifying the electronic band structure of semiconductors to produce materials with desired electronic properties.
Surface and interface effects: Surface and interface effects play a crucial role in determining the electrical conductivity of materials. They can introduce states in the bandgap and modify the energy levels of the Fermi level.
Intrinsic or undoped Fermi level: The Fermi level in an undoped semiconductor material or a perfect crystal. It is typically located midway between the valence band and the conduction band.
Extrinsic Fermi level or Equilibrium Fermi level: The Fermi level in a doped semiconductor material, where the concentration of dopants balances the intrinsic carrier concentration. The position of the Fermi level depends on the type and concentration of dopants.
Chemical potential Fermi level: The Fermi level in a material in contact with a chemical potential reservoir, where the chemical potential of the electrons is fixed. It can be higher or lower than the intrinsic Fermi level depending on the difference in chemical potentials.
Quasi-Fermi level: In a non-equilibrium situation, where the system is driven out of equilibrium by an external stimulus like an electric field, the distribution of electrons and holes varies from the equilibrium distribution. In such cases, it is useful to define a quasi-Fermi level, which describes the occupation of the available energy states in the non-equilibrium situation.
Work function Fermi level: The Fermi level in a metal, where the energy required to remove an electron from the surface of the metal is used to define the zero of energy. It can be described as the energy difference between the Fermi level and the vacuum level.
Electrochemical potential Fermi level: The Fermi level in a system with an electrochemical potential difference, where the voltage difference between the two electrodes results in a difference in the electrochemical potential of the electrons.
Ambient Fermi level: The Fermi level in a material in contact with ambient conditions, such as temperature, pressure or gas composition. It can be affected by factors like surface reactivity or exposure to radiation, which can modify the electronic states and alter the Fermi level position.
Interface Fermi level: In a system composed of multiple materials or layers, the Fermi level can vary at the interfaces due to differences in the electronic structures or the presence of interfacial states. The position of the interface Fermi level can affect the charge transfer and transport properties of the system.
"It is a thermodynamic quantity usually denoted by µ or EF for brevity."
"The Fermi level does not include the work required to remove the electron from wherever it came from."
"A precise understanding of the Fermi level... is essential to an understanding of solid-state physics."
"The Fermi level can be considered to be a hypothetical energy level of an electron, such that at thermodynamic equilibrium this energy level would have a 50% probability of being occupied at any given time."
"The position of the Fermi level in relation to the band energy levels is a crucial factor in determining electrical properties."
"The Fermi level does not necessarily correspond to an actual energy level..."
"...in an insulator the Fermi level lies in the band gap."
"nor does it require the existence of a band structure."
"Differences in Fermi level can be measured simply with a voltmeter."
"...how it relates to electronic band structure in determining electronic properties..."
"...this energy level would have a 50% probability of being occupied at any given time."
"It is a thermodynamic quantity usually denoted by µ or EF for brevity."
"...how it relates to the voltage and flow of charge in an electronic circuit..."
"...how it relates to the voltage and flow of charge in an electronic circuit..."
"...the Fermi level is a precisely defined thermodynamic quantity..."
"...how it relates to the voltage and flow of charge in an electronic circuit..."
"Differences in Fermi level can be measured simply with a voltmeter."
"The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body."
"The Fermi level does not include the work required to remove the electron from wherever it came from."