Investigation of wetting layers in InAs/GaAs self-assembled nanostructures with reflectance difference spectroscopy

TL;DR

This paper reviews recent advances in studying wetting layers in InAs/GaAs nanostructures using reflectance difference spectroscopy, highlighting how growth conditions influence wetting layer evolution and properties.

Contribution

It introduces new insights into wetting layer evolution in InAs/GaAs systems, emphasizing the role of growth conditions and different fabrication methods.

Findings

Wetting layers significantly affect nanostructure properties.

Growth interruptions influence wetting layer evolution.

Different growth modes lead to distinct wetting layer behaviors.

Abstract

As a system with both profound physics and promising application potentials, the strain-induced self-assembled semiconductor nanostructures have been investigated for decades of years. The optical and electrical properties of this system are mainly determined by the nanostructures, but can be greatly affected by the generally existent two dimensional structures from which the nanostructures evolve, the so called wetting layer (WL). The WL configurations can be varied with different growth conditions, and further influence the nanostructure morphology and properties. This is a reviewing article introducing some recent progresses in investigating the evolution of WLs in InAs/GaAs system with reflectance difference spectroscopy. Different kinds of WL evolution processes in Stranski-Krastanov growth mode are introduced. The segregation and desorption of indium atoms and the effect of growth interruption are mentioned. The existence and the evolution process of wetting layers in droplet epitaxy method are also discussed.