Carrier Concentration Disturbances in Semiconductors

Carrier concentration disturbances in semiconducting filaments are discussed by reference to the composition of the current at the end contacts. Four types of disturbance must be envisaged, of which carrier injection is the best known. Carrier exclusion and extraction have also been experimentally observed, but carrier accumulation has not yet been reported. These phenomena are discussed in terms of a unified set of equations on the assumption that the disturbances are much smaller than the equilibrium concentration of majority carriers.