Semiconductor quantum structures for applications in the near infrared and blue regions

Päivi Mattila

Semiconductor quantum structures for applications in the near infrared and blue regions

Julkaisun otsikon käännös: Puolijohdekvanttirakenteet lähi-infrapunan ja sinisen aallonpituusalueen sovelluksiin

Päivi Mattila

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Tässä väitöskirjassa tutkitaan puolijohdekvanttirakenteiden ominaisuuksien parantamista lähi-infrapunan ja sinisen aallonpituusalueilla. Tässä työssä esitetyt menetelmät käsittävät AlN passivoinnin ja GaAs-pohjaiset kvanttipisterakenteet lähi-infrapuna-alueella. Sinisellä alueella yksiulotteisia metallihiloja on valmistettu GaN-rakenteiden päälle. Kaikilla näillä on potentiaalisia sovelluksia optoelektronisissa komponenteissa kuten nanolankapohjaisissa detektoreissa, metalli-eriste-puolijohde-rakenteissa ja valodiodeissa. GaAs-rakenteet on valmistettu organometallisella kaasufaasimenetelmällä, ja AlN-kerrokset on tehty erikseen GaAs-rakenteen päälle (engl. ex situ) atomikerroskasvatusmenetelmällä. Passivoinnin toimivuus todennetaan fotoluminesenssi-, fotoreflektanssi- ja kapasitanssi-jännitemittauksin sekä aikariippuvilla fotoluminesenssimittauksilla. AlN-passivointia verrataan pelkällä plasmalla tehtyyn passivointiin, ja tulokset osoittavat, että plasmalla on myös merkitystä AlN-passivoinnissa. AlN-passivoinnin toimivuutta ei kuitenkaan voi kokonaan selittää plasmalla, ja vedyllä esitetään olevan vaikutusta passivoinnin toimivuuteen. Kun AlN-kerroksen paksuutta kasvatetaan, jännityskvanttipisteet voidaan peittää ilman, että integroitu fotoluminesenssi-intensiteetti pienenee. Lisäksi kvanttipistetilojen ja kvanttikaivon välinen energiaero (engl. energy redshift) ei muutu. Näin ollen AlN-kerrosta voidaan käyttää jännityskvanttipisterakenteiden pinnoittamiseen. GaAsN-saarekkeet on valmistettu lämpökäsittelemällä venyttävässä jännityksessä olevia GaAsN-kerroksia. Kerroksessa oleva typpi pienentää GaAs:n energia-aukkoa. Näin ollen fotoluminesenssi-intensiteetin maksimi siirtyy kohti pidempiä optisen tietoliikenteen aallonpituuksia. Sinisellä aallonpituusalueella InGaN/GaN-rakenteita karakterisoidaan fotoluminesenssi- ja reflektometrimittauksin sekä kulmariippuvilla fotoluminesenssimittauksilla. Kun polyvinyylialkoholikerros valmistetaan hilan päälle, rakenteiden emissio paranee sekä TM- että TE-polarisaatiossa. Tällöin fotoluminesessi-intensiteetti kasvaa jopa 2,8-kertaiseksi.

Julkaisun otsikon käännös	Puolijohdekvanttirakenteet lähi-infrapunan ja sinisen aallonpituusalueen sovelluksiin
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Sopanen, Markku, Vastuuprofessori Kujala, Sami, Ohjaaja Huhtio, Teppo, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-7133-6
Sähköinen ISBN	978-952-60-7132-9
Tila	Julkaistu - 2016
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

AlN passivointi
fotoluminesenssi
kvanttirakenne
plasmoni
aaltojohde

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-7132-9Lisenssi: Määrittelemätön

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@phdthesis{1e8025b0c426435bbff174d721996f55,

title = "Semiconductor quantum structures for applications in the near infrared and blue regions",

abstract = "In this work, semiconductor quantum structures are studied to show enhanced performance in the near-infrared and blue wavelength regions. The techniques presented in this thesis include AlN passivation of GaAs surfaces and GaAs-based quantum dot structures in the near-infrared region. In the blue wavelength region, one-dimensional metal gratings are fabricated on GaN structures. All of these techniques have potential applications in optoelectronic components including nanowire-based detectors, metal-insulator-semiconductor structures, and light-emitting diodes. The GaAs-based structures are fabricated by metalorganic vapor phase epitaxy, and the AlN layers are deposited ex situ by plasma-enhanced atomic layer deposition. The passivation effect is verified by photoluminescence, time-resolved photoluminescence, photoreflectance, and capacitance-voltage measurements. The comparison of pure plasma and AlN passivation shows that plasma has a role in the process. The effect cannot, however, be entirely explained by plasma, and hydrogen is suggested to affect the passivation. When the AlN layer thickness is further increased, the delicate strain-induced quantum dots are covered without reducing the integrated photoluminescence intensity. In addition, the energy redshift of the quantum dot states is not affected by the covering with AlN. Thus, AlN can be used to cover these delicate structures. GaAsN islands are fabricated on InP by annealing tensile-strained GaAsN layers. The nitrogen in the layer reduces the band gap of GaAs. Therefore, the photoluminescence intensity maximum is observed to shift towards the longer wavelengths of optical telecommunications. In the blue wavelength region, the GaN structures are characterized by photoluminescence, angle-resolved photoluminescence and reflectometry measurements. When a polyvinyl alcohol layer is fabricated on top of the InGaN/GaN sample, the enhancement of emission is observed in both TM and TE polarizations. The photoluminescence intensity is shown to increase by a factor of up to 2.8.",

keywords = "AlN passivation, photoluminescence, plasmon, quantum structure, waveguide, AlN passivointi, fotoluminesenssi, kvanttirakenne, plasmoni, aaltojohde, AlN passivation, photoluminescence, plasmon, quantum structure, waveguide",

author = "P{\"a}ivi Mattila",

year = "2016",

language = "English",

isbn = "978-952-60-7133-6",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "237",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Semiconductor quantum structures for applications in the near infrared and blue regions

AU - Mattila, Päivi

PY - 2016

Y1 - 2016

N2 - In this work, semiconductor quantum structures are studied to show enhanced performance in the near-infrared and blue wavelength regions. The techniques presented in this thesis include AlN passivation of GaAs surfaces and GaAs-based quantum dot structures in the near-infrared region. In the blue wavelength region, one-dimensional metal gratings are fabricated on GaN structures. All of these techniques have potential applications in optoelectronic components including nanowire-based detectors, metal-insulator-semiconductor structures, and light-emitting diodes. The GaAs-based structures are fabricated by metalorganic vapor phase epitaxy, and the AlN layers are deposited ex situ by plasma-enhanced atomic layer deposition. The passivation effect is verified by photoluminescence, time-resolved photoluminescence, photoreflectance, and capacitance-voltage measurements. The comparison of pure plasma and AlN passivation shows that plasma has a role in the process. The effect cannot, however, be entirely explained by plasma, and hydrogen is suggested to affect the passivation. When the AlN layer thickness is further increased, the delicate strain-induced quantum dots are covered without reducing the integrated photoluminescence intensity. In addition, the energy redshift of the quantum dot states is not affected by the covering with AlN. Thus, AlN can be used to cover these delicate structures. GaAsN islands are fabricated on InP by annealing tensile-strained GaAsN layers. The nitrogen in the layer reduces the band gap of GaAs. Therefore, the photoluminescence intensity maximum is observed to shift towards the longer wavelengths of optical telecommunications. In the blue wavelength region, the GaN structures are characterized by photoluminescence, angle-resolved photoluminescence and reflectometry measurements. When a polyvinyl alcohol layer is fabricated on top of the InGaN/GaN sample, the enhancement of emission is observed in both TM and TE polarizations. The photoluminescence intensity is shown to increase by a factor of up to 2.8.

AB - In this work, semiconductor quantum structures are studied to show enhanced performance in the near-infrared and blue wavelength regions. The techniques presented in this thesis include AlN passivation of GaAs surfaces and GaAs-based quantum dot structures in the near-infrared region. In the blue wavelength region, one-dimensional metal gratings are fabricated on GaN structures. All of these techniques have potential applications in optoelectronic components including nanowire-based detectors, metal-insulator-semiconductor structures, and light-emitting diodes. The GaAs-based structures are fabricated by metalorganic vapor phase epitaxy, and the AlN layers are deposited ex situ by plasma-enhanced atomic layer deposition. The passivation effect is verified by photoluminescence, time-resolved photoluminescence, photoreflectance, and capacitance-voltage measurements. The comparison of pure plasma and AlN passivation shows that plasma has a role in the process. The effect cannot, however, be entirely explained by plasma, and hydrogen is suggested to affect the passivation. When the AlN layer thickness is further increased, the delicate strain-induced quantum dots are covered without reducing the integrated photoluminescence intensity. In addition, the energy redshift of the quantum dot states is not affected by the covering with AlN. Thus, AlN can be used to cover these delicate structures. GaAsN islands are fabricated on InP by annealing tensile-strained GaAsN layers. The nitrogen in the layer reduces the band gap of GaAs. Therefore, the photoluminescence intensity maximum is observed to shift towards the longer wavelengths of optical telecommunications. In the blue wavelength region, the GaN structures are characterized by photoluminescence, angle-resolved photoluminescence and reflectometry measurements. When a polyvinyl alcohol layer is fabricated on top of the InGaN/GaN sample, the enhancement of emission is observed in both TM and TE polarizations. The photoluminescence intensity is shown to increase by a factor of up to 2.8.

KW - AlN passivation

KW - photoluminescence

KW - plasmon

KW - quantum structure

KW - waveguide

KW - AlN passivointi

KW - fotoluminesenssi

KW - kvanttirakenne

KW - plasmoni

KW - aaltojohde

KW - AlN passivation

KW - photoluminescence

KW - plasmon

KW - quantum structure

KW - waveguide

M3 - Doctoral Thesis

SN - 978-952-60-7133-6

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Semiconductor quantum structures for applications in the near infrared and blue regions

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

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