Electronic properties of n-i-n-i doping superlattices

Band structures of n-i-n-i doping superlattices are found using a self-consistent calculation based on the envelope function formalism. The modulation potentials, the charge density distributions, the dispersion relationships, and the occupation of the subbands in the n-i-n-i superlattices are computed and their dependence on temperature and the structural parameters of the superlattices are studied. It is found that the modulation potentials of n-i-n-i doping superlattices are weak, and quantum effects are, therefore, also weak. The density of states in n-i-n-i superlattices can be adjusted by varying the structural parameters of the superlattices. As a result, the n-i-n-i doping superlattices behave like uniformly doped semiconductors with an adjustable density of states. The density of states is found to be temperature dependent. Electron mobilities of the n-i-n-i doping superlattices are also computed. It is found that both impurity scattering processes that are observed in uniform lightly doped semiconductor and heavily doped semiconductor can coexist in the n-i-n-i doping superlattices.