Zener tunneling in semiconductor superlattices

Abstract

Characteristics of miniband tunneling and Wannier–Stark levels in semiconductorsuperlattices are studied as regards their dependence on the symmetry of the unit cells andthe type of miniband structure. We modify the k ⋅ p method into a k ⋅ v form and on this basis generalize the Zener formula for the inter-band tunneling inhomogeneous semiconductors to the case of inter-miniband tunneling in superlattices,account being taken of the inhomogeneity of the electron effective mass. The correspondingsum rule for the effective masses in such structures is obtained. We develop a unifiedmatrix approach for the calculation of the inter-miniband tunneling and Wannier–Starklevels in the case of an arbitrary number of minibands. We study the electric fielddependence of the probability of inter-miniband tunneling for an electron transferredthrough the Brillouin minizone only once. The peculiarities of the inter-minibandtransitions for the case where this transfer is repeated are also examined for various unitcells and miniband structures of the superlattice. In addition, we discuss mechanisms andspecific features of the resonant Zener tunneling and its manifestations in electrontransport.