Quasi-Fermi level

A Quasi-Fermi level is a concept used in semiconductor physics to describe the energy position of electrons or holes when the material is affected by external influences like light or electrical current. Instead of having a single, uniform energy level as in equilibrium, the electrons and holes can have different energy distributions. The Quasi-Fermi levels represent the average energy of these charge carriers under such conditions, helping scientists understand how the material behaves when it conducts electricity or responds to illumination. This concept is essential for designing and analyzing devices like solar cells and transistors.