Influence of capping layer growth mode on the photoluminescence of InAs quantum dots in silicon

TL;DR

This study investigates how different silicon capping layer growth modes affect the optical properties of InAs quantum dots in silicon, demonstrating improved photoluminescence with a two-stage growth method and analyzing electron confinement.

Contribution

It introduces a two-stage silicon overgrowth technique that enhances photoluminescence by improving heterostructure crystallinity and provides insights into electron confinement at room temperature.

Findings

Photoluminescence at 1650 nm was achieved up to 120 K.

Two-stage growth increases photoluminescence intensity.

Calculated activation energy for electron confinement.

Abstract

The influence of growth regimes of the silicon capping layer on the optical properties of heterostructures with submonolayer InAs quantum dots embedded in a silicon matrix has been studied. The photoluminescence signal at 1650 nm from submonolayer quantum dots at low temperatures up to 120 K was obtained. It was established that the use of a two-stage method of silicon overgrowing InAs nanoislands makes it possible to increase the photoluminescence intensity by improving the crystalline quality of heterostructures. Analysis of the temperature dependence allowed us to calculate an activation energy for electrons confined in the quantum dots potential well at the level of the thermal energy at room temperature.