Theory of transient spectroscopy of multiple quantum well structures

TL;DR

This paper develops an analytical model for the transient spectroscopy of quantum well structures under bias, accounting for carrier transport and electric field effects, validated by numerical simulations and useful for extracting emission times.

Contribution

It introduces a novel analytical model that considers both emission rates and carrier transport in transient spectroscopy of quantum wells, validated by simulations.

Findings

Transient current depends on emission rate and carrier transport.

Electric field nonuniformity causes step-like current behavior.

Method for extracting QW emission time from experiments.

Abstract

A theory of the transient spectroscopy of quantum well (QW) structures under a large applied bias is presented. An analytical model of the initial part of the transient current is proposed. The time constant of the transient current depends not only on the emission rate from the QWs, as is usually assumed, but also on the subsequent carrier transport across QWs. Numerical simulation was used to confirm the validity of the proposed model, and to study the transient current on a larger time scale. It is shown that the transient current is influenced by the nonuniform distribution of the electric field and related effects, which results in a step-like behavior of the current. A procedure of extraction of the QW emission time from the transient spectroscopy experiments is suggested.