Fermi Energy Concept in Semiconductors

Fermi energy in semiconductors is the energy level that indicates the highest occupied electron state at absolute zero temperature. It serves as a reference point for understanding how electrons are distributed within the material. In intrinsic (pure) semiconductors, the Fermi level lies midway between the valence band (where electrons are bound) and the conduction band (where electrons can move freely). When impurities are added (doping), the Fermi level shifts closer to either band, affecting electrical conductivity. Essentially, it helps predict how many electrons are available to conduct electricity under different conditions.