Fabrication of In(P)As Quantum Dots by Interdiffusion of P and As on InP(311)B Substrate

Kouichi Akahane,Atsushi Matsumoto,Naokatsu Yamamoto,Toshimasa Umezawa

doi:10.3390/cryst10020090

Kouichi Akahane, Atsushi Matsumoto + Show 2 more

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https://doi.org/10.3390/cryst10020090

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Abstract

Herein, we report on our investigation of a fabrication scheme for self-assembled quantum dots (QDs), which is another type of Stranski–Krastanow (S–K) growth mode. The In(P)As QD structure was formed by the irradiation of As flux on an InP(311)B surface in a molecular beam epitaxy system controlled by substrate temperature and irradiation duration. These QDs show photoluminescence at around 1500 nm, which is suitable for fiber optic communication systems. The QDs formed by this structure had high As composition because they had size, density, and emission wavelength similar to those of QDs grown by the usual S–K growth mode.

Highlights

Semiconductor quantum dots (QDs) have attracted much attention because they can confine electrons and holes three dimensionally
We found that, during the formation of QDs irradiated only by group V atoms, growth occurred on the substrate by molecular beam epitaxy (MBE), in which the group V atoms on the substrate were replaced by the irradiating atoms [14]
These results indicate that a crystalline three-dimensional nanostructure was formed, because metallic or amorphous surfaces show a halo pattern with Reflection of high-energy electron diffraction (RHEED)

Summary

Introduction

Semiconductor quantum dots (QDs) have attracted much attention because they can confine electrons and holes three dimensionally. The technique for self-assembling QDs is widely used for application to optical devices (such as semiconductor laser diodes) using the Stranski–Krastanow (S–K) growth mode because these applications do not require control of a QD position. In systems of III-V materials, techniques for self-assembling of InAs QDs on GaAs or InP substrate have been well investigated [8,9,10,11]. In the growth of self-assembled QDs, a molecular beam of group III atoms and group V atoms are usually supplied simultaneously. There are some special growth techniques such as droplet epitaxy [12,13], in which only group III atoms are supplied to the substrate at low temperature followed by irradiation with group V atoms at high temperature.

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