As an example when you connect a N-type semiconductor to a p-type one (with less Fermi energy), the carriers would move from one to another until their Fermi level become the same.You can read semiconductor device books to see further applications of Fermi energy.physio said:I understood that the fermi level is a hypothetical energy level given by the Fermi-Dirac distribution where the probability of finding an electron is exactly 50%. My question is: it always takes (Ec-Ev) energy to excite the electrons in the conduction band in an intrinsic semiconductor or (Ec-Ed), (Ec-Ea) for extrinsic semiconductors then what is the usefulness of knowing the Fermi level in the semiconductor? Why can't we do without the Fermi level.
The Fermi level is the energy level that represents the maximum energy that an electron in a semiconductor can have at absolute zero temperature. It is important in semiconductors because it determines the available energy states for electrons to occupy, which ultimately affects the electrical conductivity of the material.
The Fermi level in a semiconductor can change with temperature due to the thermal excitation of electrons. As the temperature increases, more electrons are able to gain energy and occupy higher energy states, causing the Fermi level to shift towards the conduction band.
In an intrinsic semiconductor, the Fermi level lies in the middle of the band gap and is not influenced by impurities. In an extrinsic semiconductor, the Fermi level shifts towards the energy level of the majority carrier due to the presence of impurities, resulting in an increase in conductivity.
The position of the Fermi level in a semiconductor affects the number of available energy states for electrons to occupy in the conduction and valence bands. This, in turn, affects the band gap and conductivity of the material.
Yes, the Fermi level can be manipulated in semiconductors through the addition of impurities, also known as doping. By adding specific impurities, the Fermi level can be shifted towards the conduction or valence band, altering the electrical properties of the material.