Current-voltage characteristic and stability in resonant-tunneling n-doped semiconductor superlattices

TL;DR

This paper analyzes the formation and stability of electric-field domains in doped semiconductor superlattices, providing analytical bounds for stable domain occurrence and explaining differences from Gunn diodes.

Contribution

It offers a complete analysis of stationary field profiles with two domains and derives an analytical estimate for the doping density threshold for stability.

Findings

Stable domains occur above a specific doping density.

Analytical estimation for the doping threshold.

Superlattices can exhibit self-sustained current oscillations.

Abstract

We review the occurrence of electric-field domains in doped superlattices within a discrete drift model. A complete analysis of the construction and stability of stationary field profiles having two domains is carried out. As a consequence, we can provide a simple analytical estimation for the doping density above which stable stable domains occur. This bound may be useful for the design of superlattices exhibiting self-sustained current oscillations. Furthermore we explain why stable domains occur in superlattices in contrast to the usual Gunn diode.