Photoluminescence of patterned arrays of vertically stacked InAs/GaAs quantum dots

TL;DR

This study investigates how patterned arrays of vertically stacked InAs/GaAs quantum dots grown via molecular-beam epitaxy exhibit enhanced photoluminescence, with emission intensity increasing as dot density rises due to focused ion beam patterning.

Contribution

It demonstrates selective nucleation of quantum dots at patterned sites and quantifies the relationship between array spacing and emission intensity.

Findings

Quantum dot emission observed only on patterned regions.

Emission intensity increases with decreasing array spacing.

Preferential nucleation at desired locations confirmed.

Abstract

We report on photoluminescence measurements of vertically stacked InAs/GaAs quantum dots grown by molecular-beam epitaxy on focused ion beam patterned hole arrays with varying array spacing. Quantum dot emission at 1.24 eV was observed only on patterned regions, demonstrating preferential nucleation of optically-active dots at desired locations and below the critical thickness for dot formation at these growth conditions. Photoluminescence measurements as a function of varying focused ion beam irradiated hole spacing showed that the quantum dot emission intensity increased with decreasing array periodicity, consistent with increasing dot density.