Injection in a continuum miniband: Observation of negative transconductance in a superlattice-base transistor

Abstract
We report the first observation of electron injection in a continuum miniband and of the associated negative transconductance in a semiconductor heterostructure. In a superlattice‐base unipolar transistor, electrons are injected into a miniband lying in the classical continuum of energy. They are collected by a compositionally graded collector barrier. Negative transconductance is observed due to suppression of miniband conduction in the base.