Migration enhanced epitaxy of CdSe islands on ZnSe and their optical and structural characterization

K. Leonardi; K. Ohkawa; D. Hommel; H. Selke; F. Gindele; U. Woggon

doi:10.1016/S0167-9317(98)00247-0

Migration enhanced epitaxy of CdSe islands on ZnSe and their optical and structural characterization

K. Leonardi^*, K. Ohkawa, D. Hommel, H. Selke, F. Gindele, U. Woggon

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Formation of self-assembling CdSe islands on ZnSe has been achieved using Migration Enhanced Epitaxy (MEE). Atomic Force Microscopy (AFM) images of uncapped samples show spherical islands with a diameter-to-height ratio of 4:1, which is not yet an unambiguous proof for CdSe quantum-dots. Transmission Electron Microscopy (TEM) images from samples with a ZnSe caplayer show an interrupted Quantum Well (QW) with pronounced thickness fluctuations when the CdSe exceeds its critical thickness. Compared to bulk CdSe, the Photoluminescence (PL) peak is blue-shifted by about 0.5 eV. PL Excitation (PLE) experiments indicate that the interrupted layer consists of CdSe islands embedded in Zn_1-xCd_xSe with a composition gradient. Temperature dependence of the integrated PL-intensity exhibits thermal quenching with an activation energy of about 100 meV. The red-shift of peak-energy with temperature is considerably larger than the decrease of the bandgap of bulk CdSe.

Original language	English (US)
Pages (from-to)	701-705
Number of pages	5
Journal	Microelectronic Engineering
Volume	43-44
DOIs	https://doi.org/10.1016/S0167-9317(98)00247-0
State	Published - Aug 1 1998
Externally published	Yes

Keywords

AFM
II-VI semiconductors
MBE
PL
Quantum dots
TEM

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Atomic and Molecular Physics, and Optics
Condensed Matter Physics
Surfaces, Coatings and Films
Electrical and Electronic Engineering

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10.1016/S0167-9317(98)00247-0

Cite this

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title = "Migration enhanced epitaxy of CdSe islands on ZnSe and their optical and structural characterization",

abstract = "Formation of self-assembling CdSe islands on ZnSe has been achieved using Migration Enhanced Epitaxy (MEE). Atomic Force Microscopy (AFM) images of uncapped samples show spherical islands with a diameter-to-height ratio of 4:1, which is not yet an unambiguous proof for CdSe quantum-dots. Transmission Electron Microscopy (TEM) images from samples with a ZnSe caplayer show an interrupted Quantum Well (QW) with pronounced thickness fluctuations when the CdSe exceeds its critical thickness. Compared to bulk CdSe, the Photoluminescence (PL) peak is blue-shifted by about 0.5 eV. PL Excitation (PLE) experiments indicate that the interrupted layer consists of CdSe islands embedded in Zn1-xCdxSe with a composition gradient. Temperature dependence of the integrated PL-intensity exhibits thermal quenching with an activation energy of about 100 meV. The red-shift of peak-energy with temperature is considerably larger than the decrease of the bandgap of bulk CdSe.",

keywords = "AFM, II-VI semiconductors, MBE, PL, Quantum dots, TEM",

author = "K. Leonardi and K. Ohkawa and D. Hommel and H. Selke and F. Gindele and U. Woggon",

year = "1998",

month = aug,

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doi = "10.1016/S0167-9317(98)00247-0",

language = "English (US)",

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journal = "Microelectronic Engineering",

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T1 - Migration enhanced epitaxy of CdSe islands on ZnSe and their optical and structural characterization

AU - Leonardi, K.

AU - Ohkawa, K.

AU - Hommel, D.

AU - Selke, H.

AU - Gindele, F.

AU - Woggon, U.

PY - 1998/8/1

Y1 - 1998/8/1

N2 - Formation of self-assembling CdSe islands on ZnSe has been achieved using Migration Enhanced Epitaxy (MEE). Atomic Force Microscopy (AFM) images of uncapped samples show spherical islands with a diameter-to-height ratio of 4:1, which is not yet an unambiguous proof for CdSe quantum-dots. Transmission Electron Microscopy (TEM) images from samples with a ZnSe caplayer show an interrupted Quantum Well (QW) with pronounced thickness fluctuations when the CdSe exceeds its critical thickness. Compared to bulk CdSe, the Photoluminescence (PL) peak is blue-shifted by about 0.5 eV. PL Excitation (PLE) experiments indicate that the interrupted layer consists of CdSe islands embedded in Zn1-xCdxSe with a composition gradient. Temperature dependence of the integrated PL-intensity exhibits thermal quenching with an activation energy of about 100 meV. The red-shift of peak-energy with temperature is considerably larger than the decrease of the bandgap of bulk CdSe.

AB - Formation of self-assembling CdSe islands on ZnSe has been achieved using Migration Enhanced Epitaxy (MEE). Atomic Force Microscopy (AFM) images of uncapped samples show spherical islands with a diameter-to-height ratio of 4:1, which is not yet an unambiguous proof for CdSe quantum-dots. Transmission Electron Microscopy (TEM) images from samples with a ZnSe caplayer show an interrupted Quantum Well (QW) with pronounced thickness fluctuations when the CdSe exceeds its critical thickness. Compared to bulk CdSe, the Photoluminescence (PL) peak is blue-shifted by about 0.5 eV. PL Excitation (PLE) experiments indicate that the interrupted layer consists of CdSe islands embedded in Zn1-xCdxSe with a composition gradient. Temperature dependence of the integrated PL-intensity exhibits thermal quenching with an activation energy of about 100 meV. The red-shift of peak-energy with temperature is considerably larger than the decrease of the bandgap of bulk CdSe.

KW - AFM

KW - II-VI semiconductors

KW - MBE

KW - PL

KW - Quantum dots

KW - TEM

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DO - 10.1016/S0167-9317(98)00247-0

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SN - 0167-9317

VL - 43-44

SP - 701

EP - 705

JO - Microelectronic Engineering

JF - Microelectronic Engineering

ER -

Migration enhanced epitaxy of CdSe islands on ZnSe and their optical and structural characterization

Abstract

Keywords

ASJC Scopus subject areas

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