Thermal and thermoelectric transport in nanostructures for energy applications

Taneli Juntunen

Thermal and thermoelectric transport in nanostructures for energy applications

Julkaisun otsikon käännös: Termiset ja termosähköiset ilmiöt nanorakenteissa energiasovelluksiin

Taneli Juntunen

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Lämmönhallintaan liittyvät haasteet ovat yhä keskeisemmässä roolissa moderneissa elektroniikkasovelluksissa. Nanoteknologian nopea kehitys on mahdollistanut uusia tapoja hallita lämpöenergiaa mikroskooppisessa mittakaavassa. Kaikkialla läsnä oleva lämpö voidaan lisäksi muuntaa suoraan puhtaaksi ja uusiutuvaksi sähköksi termosähköisten materiaalien avulla. Vaikka termosähköisen teknologian hyötysuhde on yhä vaatimaton, nanorakenteet parantavat termosähköistä tehokkuutta samanaikaisesti mahdollistaen materiaalien läpinäkyvyyden ja taipuisuuden. Tämä väitöskirja havainnollistaa nanomittakaavan termisiä ilmiöitä, keskittyen lämpöä kuljettaviin fononeihin sekä itsessään että laajemmin osana termosähköisiä järjestelmiä. Tutkimuksen keskeisenä tavoitteena on selvittää rakenteellisen järjestyksen ja epäjärjestyksen vaikutusta lämmönkuljetukseen monikerroksisissa ohutkalvo- ja nanolankarakenteissa. Lisäksi työssä kehitetään uusia kustannustehokkaita ja ekologisia menetelmiä skaalattavien termosähköisten rakenteiden valmistukseen anturi- ja energiankeruusovelluksiin. Työssä osoitetaan, että rajapinnoilla voidaan vaikuttaa amorfisten rakenteiden lämmönjohtavuuteen hyvin määritellyn kiderakenteen puutteesta huolimatta. Kiteisissä materiaaleissa rajapinnat voidaan sen sijaan suunnitella tavalla, joka johtaa voimakkaaseen lämmönjohtavuuden pienentymiseen johtuen koherenttien termisten fononien interferenssistä. Koherentit fononit voivat myös olla osallisia lämmönjohtavuuden pienentymiseen eri materiaalilla päällystetyissä puolijohdenanolangoissa, minkä vuoksi ydin-kuorinanolangat ovat mahdollisesti lupaavia komponentteja termosähköisiin sovelluksiin. Koherenttien fononien vaikutukset luovat lisäksi pohjaa uudelle nanofononiikan tutkimusalalle. Väitöskirja esittelee myös edistyksellisiä nanovalmistusmenetelmiä suuren mittakaavan termosähköisille nanokomposiiteille siirtämällä sinkkioksidiohutkalvojen termosähköiset ominaisuudet kolmiulotteiseen polymeerimuottiin. Tämän seurauksena rakenteen termosähköinen teho kaksinkertaistuu tasomaisiin kalvoihin verrattuna. Lisäksi työssä hyödynnetään yksinkertaisia ja skaalautuvia liuospohjaisia menetelmiä orgaanisten termosähköisten grafeeninanokomposiittien valmistukseen. Lopuksi työssä esitellään uudenlaisia nanorakenteisten termosähkösovellusten prototyyppejä, kuten mustesuihkutulostettu taipuisa termosähkögeneraattori, ensimmäinen tasomainen täysin läpinäkyvä termosähköinen pn-moduuli sekä uusi hajautettuihin termopareihin perustuva passiivinen, läpinäkyvä ja taipuisa kosketuspaneeli. Esitetyt tulokset tarjoavat sekä uutta tietoa nanomittakaavan fononisista prosesseista että uusia menetelmiä energiateknologioiden kehittämiseen. Väitöskirja tukee siten poikkitieteellistä kehitystä nanofononiikasta läpinäkyviin ja taipuisiin termosähköisiin järjestelmiin.

Julkaisun otsikon käännös	Termiset ja termosähköiset ilmiöt nanorakenteissa energiasovelluksiin
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Tittonen, Ilkka, Vastuuprofessori
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-8804-4
Sähköinen ISBN	978-952-60-8805-1
Tila	Julkaistu - 2019
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

lämmönkuljetus
termosähkö
molekyylidynamiikka
fononit
nanorakenteet

YK:n kestävän kehityksen tavoitteet

Tämä tuotos edistää seuraavia kestävän kehityksen tavoitteita:

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-8805-1

OtaNano
Rissanen, A. (Manager)
Aalto-yliopisto
Laitteistot/tilat: Facility
OtaNano Nanofab
Repo, P. (Manager) & Rissanen, A. (Other)
OtaNano
Laitteistot/tilat: Facility

Siteeraa tätä

@phdthesis{920aa6fabaa84f1f9c2b3112662caf07,

title = "Thermal and thermoelectric transport in nanostructures for energy applications",

abstract = "Issues concerning the control of thermal energy assume an ever increasing role in modern electronic technologies. In an effort to address this challenge, the rapid progress in nanotechnology has introduced new ways to control heat flow at microscopic length scales. Heat is additionally an ubiquitous energy resource and may be directly converted into clean and renewable electricity using thermoelectric materials. While the available thermoelectric conversion efficiency remains modest, nanostructures also provide means for improving the thermoelectric performance of bulk materials, concurrently promoting various desirable material attributes such as transparency and flexibility. This thesis elucidates nanoscale thermal phenomena concerning heat carrying phonons per se and as part of thermoelectric energy conversion. The main goals of the work are to explore the interplay of structural disorder and order for controlling nanoscale thermal transport in thin film multilayer and nanowire systems, and to generate new routes for fabricating economical and ecological large-area thermoelectric structures for sensing and energy harvesting applications. The thermal transport studies presented in this thesis show that thermal conductivity of amorphous nanostructures may be moderately tuned by interfaces regardless of the absence of crystalline order. In crystalline multilayers, however, interfaces may be rationally designed for an enormous reduction in thermal conductivity enabled by the wave interference of coherent thermal phonons. Coherent phonons may also contribute to thermal conductivity suppression observed in semiconductor core-shell nanowires, making them promising constituents for thermoelectric systems. Generally, manifestations of phonon coherence pave way for novel thermal design through phononic band structure engineering. The work also presents advanced nanofabrication routes for large-area thermoelectric nanocomposites. Particularly, the thermoelectric properties of zinc oxide thin films are transferred to a three-dimensional polymeric template by atomic layer deposition, allowing for a two-fold power output in reference to planar structures. In addition, scalable solution-based methods are used for facile fabrication of organic thermoelectric graphene nanocomposites. Finally, the work demonstrates new types of thermoelectric application prototypes with intriguing properties enabled by nanostructuring, including fully inkjet printed flexible thermoelectric circuits, the first planar fully transparent thermoelectric p-n modules, and a novel distributed thermocouple architecture of a transparent and flexible touch panel. The results not only provide new fundamental insight into phononic processes, but also enable new technological solutions for energy harvesting. Thus, the work has potentially profound implications on the emerging fields of nanophononic thermal engineering as well as transparent and flexible thermoelectrics.",

keywords = "thermal transport, thermoelectricity, molecular dynamics, phonons, nanostructures, l{\"a}mm{\"o}nkuljetus, termos{\"a}hk{\"o}, molekyylidynamiikka, fononit, nanorakenteet, thermal transport, thermoelectricity, molecular dynamics, phonons, nanostructures",

author = "Taneli Juntunen",

year = "2019",

language = "English",

isbn = "978-952-60-8804-4",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "205",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Thermal and thermoelectric transport in nanostructures for energy applications

AU - Juntunen, Taneli

PY - 2019

Y1 - 2019

N2 - Issues concerning the control of thermal energy assume an ever increasing role in modern electronic technologies. In an effort to address this challenge, the rapid progress in nanotechnology has introduced new ways to control heat flow at microscopic length scales. Heat is additionally an ubiquitous energy resource and may be directly converted into clean and renewable electricity using thermoelectric materials. While the available thermoelectric conversion efficiency remains modest, nanostructures also provide means for improving the thermoelectric performance of bulk materials, concurrently promoting various desirable material attributes such as transparency and flexibility. This thesis elucidates nanoscale thermal phenomena concerning heat carrying phonons per se and as part of thermoelectric energy conversion. The main goals of the work are to explore the interplay of structural disorder and order for controlling nanoscale thermal transport in thin film multilayer and nanowire systems, and to generate new routes for fabricating economical and ecological large-area thermoelectric structures for sensing and energy harvesting applications. The thermal transport studies presented in this thesis show that thermal conductivity of amorphous nanostructures may be moderately tuned by interfaces regardless of the absence of crystalline order. In crystalline multilayers, however, interfaces may be rationally designed for an enormous reduction in thermal conductivity enabled by the wave interference of coherent thermal phonons. Coherent phonons may also contribute to thermal conductivity suppression observed in semiconductor core-shell nanowires, making them promising constituents for thermoelectric systems. Generally, manifestations of phonon coherence pave way for novel thermal design through phononic band structure engineering. The work also presents advanced nanofabrication routes for large-area thermoelectric nanocomposites. Particularly, the thermoelectric properties of zinc oxide thin films are transferred to a three-dimensional polymeric template by atomic layer deposition, allowing for a two-fold power output in reference to planar structures. In addition, scalable solution-based methods are used for facile fabrication of organic thermoelectric graphene nanocomposites. Finally, the work demonstrates new types of thermoelectric application prototypes with intriguing properties enabled by nanostructuring, including fully inkjet printed flexible thermoelectric circuits, the first planar fully transparent thermoelectric p-n modules, and a novel distributed thermocouple architecture of a transparent and flexible touch panel. The results not only provide new fundamental insight into phononic processes, but also enable new technological solutions for energy harvesting. Thus, the work has potentially profound implications on the emerging fields of nanophononic thermal engineering as well as transparent and flexible thermoelectrics.

AB - Issues concerning the control of thermal energy assume an ever increasing role in modern electronic technologies. In an effort to address this challenge, the rapid progress in nanotechnology has introduced new ways to control heat flow at microscopic length scales. Heat is additionally an ubiquitous energy resource and may be directly converted into clean and renewable electricity using thermoelectric materials. While the available thermoelectric conversion efficiency remains modest, nanostructures also provide means for improving the thermoelectric performance of bulk materials, concurrently promoting various desirable material attributes such as transparency and flexibility. This thesis elucidates nanoscale thermal phenomena concerning heat carrying phonons per se and as part of thermoelectric energy conversion. The main goals of the work are to explore the interplay of structural disorder and order for controlling nanoscale thermal transport in thin film multilayer and nanowire systems, and to generate new routes for fabricating economical and ecological large-area thermoelectric structures for sensing and energy harvesting applications. The thermal transport studies presented in this thesis show that thermal conductivity of amorphous nanostructures may be moderately tuned by interfaces regardless of the absence of crystalline order. In crystalline multilayers, however, interfaces may be rationally designed for an enormous reduction in thermal conductivity enabled by the wave interference of coherent thermal phonons. Coherent phonons may also contribute to thermal conductivity suppression observed in semiconductor core-shell nanowires, making them promising constituents for thermoelectric systems. Generally, manifestations of phonon coherence pave way for novel thermal design through phononic band structure engineering. The work also presents advanced nanofabrication routes for large-area thermoelectric nanocomposites. Particularly, the thermoelectric properties of zinc oxide thin films are transferred to a three-dimensional polymeric template by atomic layer deposition, allowing for a two-fold power output in reference to planar structures. In addition, scalable solution-based methods are used for facile fabrication of organic thermoelectric graphene nanocomposites. Finally, the work demonstrates new types of thermoelectric application prototypes with intriguing properties enabled by nanostructuring, including fully inkjet printed flexible thermoelectric circuits, the first planar fully transparent thermoelectric p-n modules, and a novel distributed thermocouple architecture of a transparent and flexible touch panel. The results not only provide new fundamental insight into phononic processes, but also enable new technological solutions for energy harvesting. Thus, the work has potentially profound implications on the emerging fields of nanophononic thermal engineering as well as transparent and flexible thermoelectrics.

KW - thermal transport

KW - thermoelectricity

KW - molecular dynamics

KW - phonons

KW - nanostructures

KW - lämmönkuljetus

KW - termosähkö

KW - molekyylidynamiikka

KW - fononit

KW - nanorakenteet

KW - thermal transport

KW - thermoelectricity

KW - molecular dynamics

KW - phonons

KW - nanostructures

M3 - Doctoral Thesis

SN - 978-952-60-8804-4

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Thermal and thermoelectric transport in nanostructures for energy applications

Abstrakti

Tutkimusalat

YK:n kestävän kehityksen tavoitteet

Pääsy asiakirjaan

Sormenjälki

Laitteet

OtaNano

OtaNano Nanofab

Siteeraa tätä