Title
Transparent nanocomposite films for plastic electronic applications
Creator
Radmilović, Vuk V.
Copyright date
2016
Object Links
Select license
Autorstvo-Nekomercijalno-Bez prerade 3.0 Srbija (CC BY-NC-ND 3.0)
License description
Dozvoljavate samo preuzimanje i distribuciju dela, ako/dok se pravilno naznačava ime autora, bez ikakvih promena dela i bez prava komercijalnog korišćenja dela. Ova licenca je najstroža CC licenca. Osnovni opis Licence: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/deed.sr_LATN. Sadržaj ugovora u celini: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/legalcode.sr-Latn
Language
English
Cobiss-ID
Committee report
Theses Type
Doktorska disertacija
description
Datum odbrane: 20161209
Other responsibilities
mentor
Uskoković, Petar, 1965-
član komisije
Popović, Zoran.
član komisije
Janaćković, Đorđe, 1964-
član komisije
Radojević, Vesna, 1961-
član komisije
Spiecker, Erdmann.
Academic Expertise
Tehničko-tehnološke nauke
University
Univerzitet u Beogradu
Faculty
Tehnološko-metalurški fakultet
Alternative title
Transparentni nanokompozitni filmovi za primenu u plastičnoj elektronici
Publisher
[V. Radmilović]
Format
XXXII, 214 listova
description
Technological Engineering-Materials Engineering / Tehnološko inženjerstvo-Inženjerstvo materijala
Abstract (en)
As solar cell technology gains more and more attraction every year, research
keeps up with trends by an exponential number of published papers every year. These
papers cover a wide range of topics regarding solar cells and the individual components
of which they are comprised, which is the subject of this thesis. Different topics of
research have been addressed in order to better understand and optimize individual solar
cell components (layers) such as silver nanowires (AgNWs), AgNW based
nanocomposite and Ag dendrites for the application as transparent electrodes, polymer
nanocomposites (PNC) for the possible application as protective layers (encapsulants)
as well as organic tandem solar cells as a whole device, utilizing AgNWs as the
transparent electrode.
The first part of the thesis concentrates on AgNWs and an AgNW based
nanocomposite. These AgNWs were synthesized by a simple polyol reduction process.
The main focus of this research was elucidating the solid-state wetting and subsequently
welding mechanisms that occur during annealing of AgNWs before a layer of aluminum
doped zinc oxide (AZO) is deposited on them, for the enhancement of properties
essential for an electrode in a solar cell. Microstructural characterization using scanning
electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that
solid-state wetting and subsequent welding occurred only between nanowires whose
contact geometry is characterized by an enormous difference in radii of curvature.
Results also indicated that, for two AgNWs in contact, during annealing, the AgNW in
contact through a smaller radius of curvature dissolves, Ag atoms diffuse and are
incorporated in a welded zone between the AgNWs whose crystallographic orientation
is inherent from the AgNW in contact through a large radius of curvature. Wetting angle
between two welded AgNWs was measured to be below 4.8°, indicating almost
complete wetting. Direct atomic column measurements were performed in order to
elucidate crystal lattice distortion. Tomography was employed to better understand the
morphology of the welded zone and confirmed the welding mechanism based on cross
sectional transmission electron microscopy imaging. Electron diffraction orientation and
strain mapping were performed in order to elucidate possible strain fluctuation across
the AgNWs as well as confirm crystallographic orientation of the welded zone. Crystal
lattice distortion, directly measured by atomic column displacements in drift corrected
cross-sectional atomic resolution scanning transmission electron microscopy images of
an AgNW, prepared by focused ion beam (FIB), demonstrated non-uniform distribution
of strain in five twin segments of the nanowire...
Abstract (sr)
S obzirom na porast interesovanja za solarnim tehnologijama, istraživanja idu u
korak sa takvim trendovima što se manifestuje eksponencijalnim rastom broja
objavljenih naučnih radova svake godine. Ovi radovi pokrivaju širok spektar tema
vezanih za solarne ćelije i individualne slojeve od kojih su one sačinjene, što je i
predmet proučavanja ove teze. Istraživanja su se odvijala u nekoliko pravaca kako bi se
bolje razumeli i optimizovali individualni slojevi (komponente) solarnih ćelija kao što
su nano-žice srebra, nanokompoziti na bazi nano-žica srebra i dendriti srebra, za
primenu kao transparentne elektrode, polimerni nanokompoziti za primenu kao zaštitni
slojevi (enkapsulanati) kao i kompletne organske tandem solarne ćelije koje koriste
nano-žice srebra kao transparentne elektrode.
Prvi deo teze fokusiran je na nano-žice srebra i nanokompozite na bazi nanožica
srebra. Nano-žice su sintetisane jednostavnom metodom poliol redukcije. Osnova
ovog istraživanja bila je razumevanje mehanizama kvašenja u čvrstom stanju i
zavarivanja do kojih dolazi prilikom zagrevanja nano-žica, pre nego što je sloj cink
oksida dopiran aluminijumom nanešen radi poboljšanja svojstava, od suštinskog značaja
za elektrodu u solarnoj ćeliji. Mikrostrukturna karakterizacija korišćenjem skenirajuće
elektronske mikroskopije (SEM) i transmisione elektronske mikroskopije (TEM) otkrila
je da se kvašenje i zavarivanje odvijaju samo između nano-žica čiji su poluprečnici
zakrivljenja u tački dodira veoma različiti. Rezultati su takođe pokazali da, kod dve
nano-žice u kontaktu, prilikom zagrevanja, atomi srebra iz područja nano-žice u
kontaktu malog poluprečnika zakrivljenja difunduju i ugrađuju se u zonu zavarenog
spoja, koja povezuje dve nano-žice. Kristalografska orijentacija zavarenog spoja
nasleđena je od nano-žice u velikog poluprečnika zakrivljenja u tački dodira. Ugao
kvašenja između dve nano-žice manji je od 4.8°, što je indikator potpunog kvašenja.
Tomografija je korišćena kako bi se bolje razumela morfologija zavarenog spoja i
potvrdio mehanizam zavarivanja, ustanovljen na osnovu rezultata transmisione
elektronske mikroskopije poprečnih preseka nano-žica. Mapiranje orientacije i
naprezanja elektroskom difrakcijom urađeno je kako bi se utvrdila raspodela naprezanja
u nano-žicama i potvrdila kristalografska orijentacija zavarene zone. Distorzija kristalne
rešetke direktno je merena mapiranjem pomeranja atomskih kolona na slikama
skenirajuće transmisione elektronske mikroskopije poprečnih preseka nano-žica,
pripremljenih fokusiranim jonskim snopom (FIB metodom). Ustanovljena je
neravnomerna raspodela naprezanja u dvojnikovanim segmentima nano-žica...
Authors Key words
silver nanowires, organic solar cells, tandem solar cells, silver dendrites,
twinning, polymer nanocomposites, polyvinyl butyral, carbon nanotubes, graphene,
transmission electron microscopy
Authors Key words
nanožice srebra, organske solarne ćelije, tandem solarne ćelije, dendriti
srebra, dvojnikovanje, polimerni nanokompoziti, polivinil butiral, ugljenične nanocevi,
grafin, transmisiona elektronska mikroskopija
Classification
621.383.51:66.017(043.3)
Type
Tekst
Abstract (en)
As solar cell technology gains more and more attraction every year, research
keeps up with trends by an exponential number of published papers every year. These
papers cover a wide range of topics regarding solar cells and the individual components
of which they are comprised, which is the subject of this thesis. Different topics of
research have been addressed in order to better understand and optimize individual solar
cell components (layers) such as silver nanowires (AgNWs), AgNW based
nanocomposite and Ag dendrites for the application as transparent electrodes, polymer
nanocomposites (PNC) for the possible application as protective layers (encapsulants)
as well as organic tandem solar cells as a whole device, utilizing AgNWs as the
transparent electrode.
The first part of the thesis concentrates on AgNWs and an AgNW based
nanocomposite. These AgNWs were synthesized by a simple polyol reduction process.
The main focus of this research was elucidating the solid-state wetting and subsequently
welding mechanisms that occur during annealing of AgNWs before a layer of aluminum
doped zinc oxide (AZO) is deposited on them, for the enhancement of properties
essential for an electrode in a solar cell. Microstructural characterization using scanning
electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that
solid-state wetting and subsequent welding occurred only between nanowires whose
contact geometry is characterized by an enormous difference in radii of curvature.
Results also indicated that, for two AgNWs in contact, during annealing, the AgNW in
contact through a smaller radius of curvature dissolves, Ag atoms diffuse and are
incorporated in a welded zone between the AgNWs whose crystallographic orientation
is inherent from the AgNW in contact through a large radius of curvature. Wetting angle
between two welded AgNWs was measured to be below 4.8°, indicating almost
complete wetting. Direct atomic column measurements were performed in order to
elucidate crystal lattice distortion. Tomography was employed to better understand the
morphology of the welded zone and confirmed the welding mechanism based on cross
sectional transmission electron microscopy imaging. Electron diffraction orientation and
strain mapping were performed in order to elucidate possible strain fluctuation across
the AgNWs as well as confirm crystallographic orientation of the welded zone. Crystal
lattice distortion, directly measured by atomic column displacements in drift corrected
cross-sectional atomic resolution scanning transmission electron microscopy images of
an AgNW, prepared by focused ion beam (FIB), demonstrated non-uniform distribution
of strain in five twin segments of the nanowire...
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