holedoped

Hole-doped refers to the introduction of positive charge carriers, or holes, into a material. Hole doping creates acceptor states that capture electrons, leaving mobile holes that can carry electrical current. This is the primary mechanism behind p-type conduction in many materials and is also a key feature in certain correlated oxides and superconductors.

In semiconductors, hole-doping is achieved by adding acceptor impurities that have fewer valence electrons than the host atoms. For example, boron doping of silicon introduces acceptor levels just above the valence band. Electrons from the valence band fill these acceptor states, leaving holes that participate in conduction. The resulting p-type material has holes as the majority carriers, with conductivity governed by hole mobility and concentration.

In oxide superconductors and related materials, hole doping is often accomplished by chemical substitution or by adjusting oxygen content to alter the hole density in copper-oxide (CuO2) planes. A classic example is La2−xSrxCuO4, where substituting Sr2+ for La3+ introduces holes. In cuprates, there is a characteristic dependence of properties on the hole concentration, with superconductivity emerging at certain doping levels and typically diminishing at very high or very low hole densities. Oxygen content control, as in YBa2Cu3O7−δ, similarly tunes hole concentration.

Measurement and interpretation rely on the sign and magnitude of transport coefficients such as the Hall coefficient and Seebeck coefficient, which indicate hole-dominated transport. The term “hole-doped” is commonly contrasted with “electron-doped” materials, where electrons are the majority carriers.