Superlattice with hot electron injection: an approach to a Bloch oscillator

TL;DR

This paper explores a semiconductor superlattice with hot electron injection, demonstrating how it can shift the negative differential conductivity to higher frequencies and enable THz Bloch oscillators.

Contribution

It introduces a novel approach using hot electron injection to control frequency behavior and suppress domain instability in superlattices for THz applications.

Findings

Negative differential conductivity shifted to higher frequencies

Positive dc differential conductivity achieved

Potential for THz Bloch oscillator development

Abstract

A semiconductor superlattice with hot electron injection into the miniband is considered. The injection changes the stationary distribution function and results in a qualitative change of the frequency behaviour of the differential conductivity. In the regime with Bloch oscillating electrons and injection into the upper part of the miniband the region of negative differential conductivity is shifted from low frequencies to higher frequencies. We find that the dc differential conductivity can be made positive and thus the domain instability can be suppressed. At the same time the high-frequency differential conductivity is negative above the Bloch frequency. This opens a new way to make a Bloch oscillator operating at THz frequencies.