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Technology development for a single-photon source; Technologieentwicklung fuer eine Einzelphotonenquelle

Abstract

The growth of InAs-quantum dots on GaAs-substrate is established concerning low quantum dot densities (ca. 1 pro {mu}m{sup 2}) and high densities (> 100 pro {mu}m{sup 2}). However it is not possible to reach the telecommunication wavelength regime around 1.55 {mu}m with InAs-quantum dots on GaAs-substrate. In contrast to this, InP based materials, in general, provide the emission wavelength of 1.55 {mu}m. But the effort to fabricate InAs nanostructures on InP based material system by molecular beam epitaxy does not lead to quantum dots but in general to quantum dashes, which arise in high surface densities. To enable the growth of InAs-quantum dots based on InP several detailed growth studies on to InP-substrate lattice matched matrix material Al{sub x}Ga{sub y}In{sub 1-x-y}As were performed. Thereby the influence of growth rate, growth temperature, InAs coverage and the indium content on the growth surface have been investigated. InAs has been deposited on a thin indiumfree ''sublayer''. The corresponding growth studies showed that a 0.6 nm thick GaSb sublayer is the best choice. Using this technique quantum dots with surface densities from 1 to 150 per {mu}m{sup 2} could be realized. To make low quantum dot densities also on layers containing much aluminium possible,  More>>
Authors:
Publication Date:
Aug 02, 2011
Product Type:
Thesis/Dissertation
Report Number:
INIS-DE-1231
Resource Relation:
Other Information: TH: Diss. (Dr.rer.nat.); Related Information: Selected Topics of Semiconductor Physics and Technology v. 132
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 36 MATERIALS SCIENCE; ALUMINIUM ARSENIDES; BAND THEORY; CHEMICAL COMPOSITION; ELECTROLUMINESCENCE; ELECTRONIC STRUCTURE; EMISSION SPECTRA; ENERGY GAP; ETCHING; GALLIUM ANTIMONIDES; GALLIUM ARSENIDES; INDIUM ARSENIDES; INDIUM PHOSPHIDES; INFRARED SPECTRA; LAYERS; LIGHT SOURCES; NEAR INFRARED RADIATION; PHOTON EMISSION; QUANTUM DOTS; SPECTRAL SHIFT; STARK EFFECT; SUBSTRATES; SURFACES; THIN FILMS; TUNING
OSTI ID:
21529804
Research Organizations:
Technische Univ. Muenchen, Garching (Germany). Walter-Schottky-Inst. fuer Physikalische Grundlagen der Halbleiterelektronik; Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Physik
Country of Origin:
Germany
Language:
German
Other Identifying Numbers:
Other: ISBN 978-3-941650-32-9; TRN: DE12F3001
Availability:
Commercial reproduction prohibited; INIS; OSTI as DE21529804
Submitting Site:
DEN
Size:
163 pages
Announcement Date:
Mar 08, 2012

Citation Formats

Enzmann, Roland. Technology development for a single-photon source; Technologieentwicklung fuer eine Einzelphotonenquelle. Germany: N. p., 2011. Web.
Enzmann, Roland. Technology development for a single-photon source; Technologieentwicklung fuer eine Einzelphotonenquelle. Germany.
Enzmann, Roland. 2011. "Technology development for a single-photon source; Technologieentwicklung fuer eine Einzelphotonenquelle." Germany.
@misc{etde_21529804,
title = {Technology development for a single-photon source; Technologieentwicklung fuer eine Einzelphotonenquelle}
author = {Enzmann, Roland}
abstractNote = {The growth of InAs-quantum dots on GaAs-substrate is established concerning low quantum dot densities (ca. 1 pro {mu}m{sup 2}) and high densities (> 100 pro {mu}m{sup 2}). However it is not possible to reach the telecommunication wavelength regime around 1.55 {mu}m with InAs-quantum dots on GaAs-substrate. In contrast to this, InP based materials, in general, provide the emission wavelength of 1.55 {mu}m. But the effort to fabricate InAs nanostructures on InP based material system by molecular beam epitaxy does not lead to quantum dots but in general to quantum dashes, which arise in high surface densities. To enable the growth of InAs-quantum dots based on InP several detailed growth studies on to InP-substrate lattice matched matrix material Al{sub x}Ga{sub y}In{sub 1-x-y}As were performed. Thereby the influence of growth rate, growth temperature, InAs coverage and the indium content on the growth surface have been investigated. InAs has been deposited on a thin indiumfree ''sublayer''. The corresponding growth studies showed that a 0.6 nm thick GaSb sublayer is the best choice. Using this technique quantum dots with surface densities from 1 to 150 per {mu}m{sup 2} could be realized. To make low quantum dot densities also on layers containing much aluminium possible, the Al{sub x}Ga{sub y}In{sub 1-x-y}As alloy was grown in the digital alloy growth mode, that is to say the pseudo binaries Al{sub 0,48}In{sub 0,52}As and Ga{sub 0,47}In{sub 0,53}As are grown by the second. By varying the bandgap of the matrix material, viz. by varying the aluminum content, single quantum dots emitting in the range from 1100 nm to 1560 nm could be realized. This way as well the optical O-band (1.3 {mu}m) with an aluminum content of 13% as the optical C-band (1.55 {mu}m) with an aluminum content of 4% could be realized. Another possibility to tailor the emission wavelength of quantum dots are so called stacked dots. In the process two layer of quantum dots, separated with a thin spacer layer, were deposited upon each other. By this way a redshift of the emission from 1.3 {mu}m to 1.5 {mu}m was obtained. To achieve high collection efficiency, the quantum dots should be embedded into photonic crystals. An ArCl{sub 2}-etch-process was developed which enables the etch of small features in Al{sub x}Ga{sub y}In{sub 1-x-y}As material system to transfer the Si{sub 3}N{sub 4}-pattern into the semiconductor. Using this process the fabricated photonic crystals with L3-cavities had Q-factors around 2200. Any concept using a cavity needs a mechanism to control the frequency-detuning between the mode and the quantum dots, due to the inhomogeneous frequency broadening of the quantum dots. Thus an in-situ tuning mechanism is required for adjusting the emission wavelength of the quantum dot or cavity mode, respectively. This concept intents to use the quantum confined Stark effect (QCSE) to force the emission of a single photon out of a quantum dot into the photonic crystal mode. This is realized using a reversed biased Schottky contact to cause a red-shift of the emission of a single quantum dot. Electroluminescence measurements on the device show, that even with very low currents of 14.5 {mu}A the saturation intensity of single quantum dots could be reached. (orig.)}
place = {Germany}
year = {2011}
month = {Aug}
}