Electroluminescence on-off ratio control of n-i-n GaAs/AlGaAs-based resonant tunneling structures

TL;DR

This study investigates the electroluminescence behavior of GaAs/AlGaAs resonant tunneling diodes, revealing mechanisms for controlling the EL on-off ratio and demonstrating potential for high-speed opto-electronic applications.

Contribution

It uncovers the EL on-off ratio enhancement mechanism and demonstrates tuning via series resistance, advancing the understanding of EL control in RTDs.

Findings

EL on-off ratio can be enhanced by 2 orders of magnitude during current transition.

Series resistance tuning can increase EL on-off ratio by up to 6 orders of magnitude.

EL states can be directly or inversely related to tunneling current states.

Abstract

We explore the nature of the electroluminescence (EL) emission of purely n-doped GaAs/AlGaAs resonant tunneling diodes (RTDs) and the EL evolution with voltage. A singular feature of such a device is unveiled when the electrical output current changes from high to low and the EL on-off ratio is enhanced by 2 orders of magnitude compared to the current on-off ratio. By combining the EL and current properties, we are able to identify two independent impact ionization channels associated with the coherent resonant tunneling current and the incoherent valley current. We also perform the same investigation with an associated series resistance, which induces a bistable electrical output in the system. By simulating a resistance variation for the current-voltage and the EL, we are able to tune the EL on-off ratio by up to 6 orders of magnitude. We further observe that the EL on and off states can be either direct or inverted compared to the tunneling current on and off states. This electroluminescence, combined with the unique RTD properties such as the negative differential resistance (NDR) and high frequency operation, enables the development of high speed functional opto-electronic devices and optical switches.