Radiative Recombination Spectra of Heavily p-Type delta-Doped Gaas/Alas MQWs

TL;DR

This paper investigates the photoluminescence properties of heavily Be delta-doped GaAs/AlAs quantum wells, analyzing recombination mechanisms and the Mott transition at different temperatures using experimental data and simple theoretical modeling.

Contribution

It provides new insights into the PL emission mechanisms and estimates the critical impurity concentration for the Mott transition in delta-doped GaAs/AlAs MQWs.

Findings

Identification of excitonic and free carrier PL emissions below and above the Mott transition.

Estimation of the critical impurity concentration (~3×10^12 cm^-2) for the Mott transition.

Analysis of temperature effects on PL properties.

Abstract

We present a study of the photoluminescence (PL) properties of heavily Be delta-doped GaAs/AlAs multiple quantum wells measured at room and liquid nitrogen temperatures. Possible mechanisms for photocarriers recombination are discussed, with a particular focus on the peculiarities of the excitonic and free carriers-acceptors PL emissions occurring below and above the Mott metal-insulator transition. Moreover, based on a simple theoretical model, it is found that the critical impurities concentration to observe the Mott transition in the MQW samples exhibiting 15 nm wells width and 5 nm-thick barrier layers is about 3 10E12 cm-2.