Difference Between Fermi Energy and Fermi Level

Thekey differencebetween Fermi energy and Fermi level is thatFermi energy is the energy of fermi level, whereas Fermi level is a measure of least tightly bound electrons within a solid.

The terms fermi energy and Fermi level are named after the physicist Enrico Fermi. Fermi energy is the value of energy for a Fermi level at absolute zero temperature (at 0 K) while the Fermi level is the chemical potential of electrons.

CONTENTS

1.Overview and Key Difference
2.What is Fermi Energy
3.What is Fermi Level
4.Side by Side Comparison –Fermi Energy vs Fermi Level in Tabular Form
5.概括

What is Fermi Energy?

Fermi energy is the value of energy for a Fermi level at absolute zero temperature (at 0 K). It is the maximumkinetic energyan electron can have at this temperature. Moreover, the value of Fermi energy is constant for a particular solid. We can define the term Fermi energy as the highest occupied energy level of a material at absolute zero temperature. In other words, all the electrons of a solid tend to occupy energy states at or below the solid’s Fermi energy at 0 K temperature.

In metals, Fermi energy gives the velocity of electrons during conduction. Therefore, during the conduction of metals, only electrons having energy close to the Fermi energy will contribute to the process.

Furthermore, the concept of Fermi energy is important in describing the behaviour of semiconductors. For instance, n-type semiconductors have their fermi energy close to theconduction band. In contrast, p-type semiconductors have their fermi energy close to the价带.

What is Fermi Level?

Fermi level is the chemical potential of electrons. It is an energy level in which the probability of finding an electron is 50%. Itis the highest occupied molecular orbital in the valence band at 0 K. Therefore, there are many vacant states to accept electrons. The Fermi level is located at the bandgap, between the conduction band and valence band.

What is the Difference Between Fermi Energy and Fermi Level?

费米能是在绝对零温度（0 K）下FERMI水平的能量值，而费米水平是电子的化学潜力。So, we can say that the key difference between fermi energy and Fermi level is that Fermi energy is the energy of Fermi level whereas Fermi level is a measure of least tightly bound electrons within a solid.

Below infographic provides additional details on the difference between fermi energy and Fermi level.

概括– Fermi Energy vs Fermi Level

费米能是在绝对零温度（0 K）下FERMI水平的能量值，而费米水平是电子的化学潜力。因此，费米能量和费米水平之间的关键差异是费米能是费米水平的能量，而费米水平是固体内紧密结合的电子的量度。

Reference:

1.“什么是费米能源？- 物理学。”Metropolia Confluence,Available here.

Image Courtesy:

1. “BandGap-Comparison-withfermi-E” – No machine-readable author provided. S-kei assumed (based on copyright claims). – No machine-readable source provided. Own work assumed (based on copyright claims)(CC BY-SA 2.5)viaCommons Wikimedia