Theory of Zener Tunneling and Wannier-Stark States in Semiconductors

摘要

A general multiband and multichannel scattering theory of the current inmesoscopic device structures is developed and applied to the Zener diode. It takes into account the realistic electronic structure, its modification by the high electric field, and the field free contact regions in a nonperturbative manner. This theory elucidates the interplay between Zener tunneling and Wannier-Stark resonances. Quantitative conditions for the occurrence of Wannier-Stark oscillations in the current of a bulk semiconductor or superlattice are derived. It is predicted that Wannier-Stark resonances are detectable in the interband tunneling current of highly doped submicrometer P-I-N diodes with very short I zones. We show that there are two regimes in the Zener tunneling current: a low field or Zener regime where the conductance is a smooth function of the applied voltage, and a high-field or Stark regime where Wannier-Stark resonances are induced.