Impact of Nitrogen incorporation on pseudomorphic site-controlled quantum dots grown by Metalorganic Vapour Phase Epitaxy

TL;DR

This study investigates how nitrogen incorporation affects the optical properties of site-controlled quantum dots grown by MOCVD, revealing unexpected antibinding behavior, long exciton lifetimes, and minimal fine structure splitting.

Contribution

It provides new insights into the optical characteristics of nitrogen-doped quantum dots grown by MOCVD, highlighting properties previously unreported in such structures.

Findings

Antibinding exciton/biexciton behavior observed.

Long neutral exciton lifetimes up to 7 ns.

Nearly zero fine structure splitting in most dots.

Abstract

We report on some surprising optical properties of diluted nitride InGaAs_(1-y)N_y /GaAs (y<<1) pyramidal site-controlled quantum dots, grown by metalorganic vapor phase epitaxy on patterned GaAs (111)B substrates. Microphotoluminescence characterizations showed antibinding exciton/ biexciton behavior, a spread of exciton lifetimes in an otherwise very uniform sample, with unexpected long neutral exciton lifetimes (up to 7 ns) and a nearly zero fine structure splitting on a majority of dots.