InP-quantum dots in Al0.20Ga0.80InP with different barrier configurations

TL;DR

This study investigates how different barrier configurations, including tunnel barriers, affect the optical efficiency of InP quantum dots in AlGaInP, demonstrating significant efficiency improvements at higher temperatures.

Contribution

It provides a systematic analysis of barrier configurations and introduces tunnel barriers to enhance quantum dot optical performance.

Findings

Internal quantum efficiency increased up to 20 times at elevated temperatures

Barrier configuration influences confinement energy and optical properties

Incorporation of tunnel barriers improves temperature stability of emission

Abstract

Systematic ensemble photoluminescence studies have been performed on type-I InP-quantum dots in Al0.20Ga0.80InP barriers, emitting at approximately 1.85 eV at 5 K. The influence of different barrier configurations as well as the incorporation of additional tunnel barriers on the optical properties has been investigated. The confinement energy between the dot barrier and the surrounding barrier layers, which is the sum of the band discontinuities for the valence and the conduction bands, was chosen to be approximately 190 meV by using Al0.50Ga0.50InP. In combination with 2 nm thick AlInP tunnel barriers, the internal quantum efficiency of these barrier configurations can be increased by up to a factor of 20 at elevated temperatures with respect to quantum dots without such layers.