Optical characteristics of type?II hexagonal?shaped GaSb quantum dots on GaAs synthesized using nanowire self?growth mechanism from Ga metal droplet

Title
Optical characteristics of type?II hexagonal?shaped GaSb quantum dots on GaAs synthesized using nanowire self?growth mechanism from Ga metal droplet
Authors
송진동Min BaikJi-hoon KyhmHang-Kyu KangKwang-Sik JeongJong Su KimMann-Ho Cho
Keywords
type-II; GaSb; Nanowire; droplet
Issue Date
2021-04
Publisher
Scientific Reports
Citation
VOL 11, 7699
Abstract
We report the growth mechanism and optical characteristics of type-II band-aligned GaSb quantum dots (QDs) grown on GaAs using a droplet epitaxy-driven nanowire formation mechanism with molecular beam epitaxy. Using transmission electron microscopy and scanning electron microscopy images, we confrmed that the QDs, which comprised zinc-blende crystal structures with hexagonal shapes, were successfully grown through the formation of a nanowire from a Ga droplet, with reduced strain between GaAs and GaSb. Photoluminescence (PL) peaks of GaSb capped by a GaAs layer were observed at 1.11 eV, 1.26 eV, and 1.47 eV, assigned to the QDs, a wetting-like layer (WLL), and bulk GaAs, respectively, at the measurement temperature of 14 K and excitation laser power of 30 mW. The integrated PL intensity of the QDs was signifcantly stronger than that of the WLL, which indicated well-grown GaSb QDs on GaAs and the generation of an interlayer exciton, as shown in the power- and temperature-dependent PL spectra, respectively. In addition, time-resolved PL data showed that the GaSb QD and GaAs layers formed a self-aligned type-II band alignment; the temperature-dependent PL data exhibited a high equivalent internal quantum efciency of 15± 0.2%.
URI
http://pubs.kist.re.kr/handle/201004/73074
ISSN
2045-2322
Appears in Collections:
KIST Publication > Article
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE