Current responsivity of semiconductor superlattice THz-photon detectors

TL;DR

This paper models the current responsivity of semiconductor superlattice THz-photon detectors, showing that hybrid plasma-Bloch oscillations significantly influence their performance and that optimized designs can outperform traditional detectors at room temperature.

Contribution

It introduces an equivalent circuit model accounting for parasitic losses and excitation of plasma-Bloch oscillations, providing insights into optimizing superlattice detector responsivity.

Findings

Responsivity can reach 2-3 A/W in the 1-3 THz band.

Hybrid plasma-Bloch oscillations strongly affect responsivity and frequency response.

Properly designed superlattice detectors can outperform conventional Schottky devices at room temperature.

Abstract

The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector antenna and the superlattice in the presence of parasitic losses. Calculations performed for currently available superlattice diodes show that both the magnitudes and the roll-off frequencies of the responsivity are strongly influenced by an excitation of hybrid plasma-Bloch oscillations which are found to be eigenmodes of the system in the THz- frequency band. The expected room temperature values of the responsivity (2-3 A/W in the 1-3 THz-frequency band) range up to several percents of the quantum efficiency $e/\hbar\omega$ of an ideal superconductor tunnel junction detector. Properly designed semiconductor superlattice detectors may thus demonstrate better room temperature THz-photon responsivity than conventional Schottky junction devices.