Fermi energy of a metal separates the filled states and empty states at 0 K.
Fermi energy acts as a reference energy level. Based on its value, the number of free electrons per unit volume in a metal is determined
Therefore the electrical conductivity of a metal depends on its Fermi energy.
In explaining any physical property like electrical conductivity, thermal conductivity, specific heat, susceptibility or optical absorption only Fermi level electrons are used.
In the case of semiconductors or insulators Fermi energy level is in the band gap situated between the conduction band and valence band. Here the position of Fermi level varies with temperature and carrier concentration. Thus the value of the Fermi energy determines the electrical conductivity of semiconductors and insulators also.
Effective mass of electrons
When an electron in a periodic potential is accelerated relative to the lattice in an electric field or magnetic field, then the mass of that electron is called effective mass. Consider that an external electric field, is applied to an electron of change, q and mass, m inside the crystal.
Fermi energy acts as a reference energy level. Based on its value, the number of free electrons per unit volume in a metal is determined
Therefore the electrical conductivity of a metal depends on its Fermi energy.
In explaining any physical property like electrical conductivity, thermal conductivity, specific heat, susceptibility or optical absorption only Fermi level electrons are used.
In the case of semiconductors or insulators Fermi energy level is in the band gap situated between the conduction band and valence band. Here the position of Fermi level varies with temperature and carrier concentration. Thus the value of the Fermi energy determines the electrical conductivity of semiconductors and insulators also.
Effective mass of electrons
When an electron in a periodic potential is accelerated relative to the lattice in an electric field or magnetic field, then the mass of that electron is called effective mass. Consider that an external electric field, is applied to an electron of change, q and mass, m inside the crystal.
No comments:
Post a Comment