Fine-tunable near-critical Stranski-Krastanov growth of InAs/InP quantum dots

TL;DR

This paper presents a method to precisely control the density and size of InAs/InP quantum dots during Stranski-Krastanov growth, enabling the production of well-isolated quantum dot emitters suitable for telecom applications.

Contribution

It introduces a near-critical growth regime that allows independent tuning of quantum dot density and size, advancing controlled synthesis for quantum photonics.

Findings

Quantum dot density can be tuned from 10^7 to 10^10 cm^-2.

Size and emission wavelength of quantum dots can be independently controlled.

Low-density ensembles produce isolated emission lines in the telecom C-band.

Abstract

Emerging applications of self-assembled semiconductor quantum dot (QD)-based nonclassical light sources emitting in the telecom C-band (1530 to 1565 nm) present challenges in terms of controlled synthesis of their low-density ensembles, critical for device processing with an isolated QD. This work shows how to control the surface density and size of InAs/InP quantum dots over a wide range by tailoring the conditions of Stranski-Krastanow growth. We demonstrate that in the near-critical growth regime, the density of quantum dots can be tuned between $10^7$ and $10^{10} cm^{-2}$. Furthermore, employing both experimental and modeling approaches, we show that the size (and therefore the emission wavelength) of InAs nanoislands on InP can be controlled independently from their surface density. Finally, we demonstrate that our growth method gives low-density ensembles resulting in well-isolated QD-originated emission lines in the telecom C-band.