Nano Science and Technology InstituteNano Science and Technology Institute
Nano Science and Technology Institute 2003 NSTI Nanotechnology Conference & Trade Show
Nanotech 2003
BioNano 2003
Index of Authors
2003 Sub Sections
Press Room
NSTI Events
Site Map
Nanotech Proceedings
Nanotechnology Proceedings
Supporting Organizations
Supporting Organizations
Event Contact
696 San Ramon Valley Blvd., Ste. 423
Danville, CA 94526
Ph: (925) 353-5004
Fx: (925) 886-8461

Optical characteristics of InAs quantum dots influenced by AlGaAs/GaAs superlattice barriers

Hyonkwang Choi, Yonkil Jeong, Yumi Park, Jewon Lee, Jae-Young Leem, and Minhyon Jeon*
Department of Broadband information and communication, Inje University, KR

Keywords: quantum dot, GaAs, superlattice, MBE

We investigated the effect of AlGaAs/GaAs superlattice barriers on the optical properties of InAs quantum dots (QDs) by using photoluminescence (PL) spectroscopy. The samples used in the present work were grown by molecular beam epitaxy (MBE) on the (100) semi-insulated GaAs substrates. Five different types of sample structures were designed and grown to investigate the effects of AlGaAs/GaAs superlattice barriers. In order to identify the effect superlattice barrier, simple GaAs/InAs QD/GaAs structure was also grown as a reference. The structures are GaAs/InAs/GaAs (S1) ,GaAs/Al0.112Ga0.888As/InAs/Al0.111Ga0.888As/GaAs(S2), GaAs/Al0.285Ga0.715As/InAs/Al0.285Ga0.715As/GaAs (S3), GaAs/ {Al0.112Ga0.888As/GaAs}´10/InAs/{GaAs/Al0.112Ga0.888As}´10/GaAs (S4) and GaAs/ {Al0.285Ga0.715As/GaAs}´10/InAs/{GaAs/Al0.285Ga0.715As}´10/GaAs (S5). The schematic diagram for sample structures is shown in Figure 1 in terms of band gap. The photoluminescence spectra were recorded and analyzed. In case of the sample S2 and S3, the emission peak positions from InAs QDs embedded in thick AlGaAs barrier were blue-shifted from that of reference sample(S1) by the amount of 55 meV and 102 meV, respectively. However, the PL intensity was drastically decreased with large broadening in PL linewidth from 44 meV to 75 and 80 meV for the ground state. On the other hand, in case of InAs QDs inserted in between AlGaAs/GaAs superlattice barriers, the emission peak position was blue-shifted just like the InAs QDs with thick AlGaAs barrier. However, the linewidths and PL intensity were greatly improved. Figure 2 show the PL spectra for samples of five different structures. From these results, the AlGaAs/GaAs superlattice barriers can effectively change the emission peak position of InAs QDs without much sacrifying the optical characteristics of QD structures.

NSTI Nanotech 2003 Conference Technical Program Abstract

Featured Sponsors
Nanotech Sponsors
News Headlines
NSTI Online Community

© Nano Science and Technology Institute, all rights reserved.
Terms of use | Privacy policy | Contact