AlGaAs/GaAs/AlGaAs quantum wells as a sensitive tool for the MOVPE reactor environment

TL;DR

This study introduces a GaAs/AlGaAs quantum well structure as a sensitive probe to evaluate the performance of arsine purifiers in MOVPE systems, revealing the need for purifications below 1ppb for high-quality growth.

Contribution

The paper demonstrates the use of quantum wells as a sensitive, simple tool to assess purifier performance in MOVPE, providing a new method for reactor environment monitoring.

Findings

Quantum wells show narrow photoluminescence linewidths indicating high purity.

Purifier performance varies significantly between commercial products.

Purifications below 1ppb are necessary for optimal quantum well quality.

Abstract

We present in this work a simple Quantum Well (QW) structure consisting of GaAs wells with AlGaAs barriers as a probe for measuring the performance of arsine purifiers within a MetalOrganic Vapour Phase Epitaxy system. Comparisons between two different commercially available purifiers are based on the analysis of low temperature photoluminescence emission spectra from thick QWs, grown on GaAs substrates misoriented slightly from (100). Neutral excitons emitted from these structures show extremely narrow linewidths, comparable to those which can be obtained by Molecular Beam Epitaxy in an ultra-high vacuum environment, suggesting that purifications well below the 1ppb level are needed to achieve high quality quantum well growth.