Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Microwave assisted rapid growth of flat ZnO(0001) platelets
Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörsvetenskap och fysik. (Materialfysik)
Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörsvetenskap och fysik. (Fysik)
2013 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Ort, förlag, år, upplaga, sidor
2013.
Nyckelord [en]
ZnO, Nanostructures, Microwave assisted growth
Nationell ämneskategori
Den kondenserade materiens fysik Nanoteknik
Forskningsämne
Fysik
Identifikatorer
URN: urn:nbn:se:kau:diva-27153OAI: oai:DiVA.org:kau-27153DiVA, id: diva2:619262
Projekt
Bio2Mat
Forskningsfinansiär
VinnovaTillgänglig från: 2013-05-02 Skapad: 2013-05-02 Senast uppdaterad: 2014-02-10Bibliografiskt granskad
Ingår i avhandling
1. Growth and Characterization of ZnO Nanocrystals
Öppna denna publikation i ny flik eller fönster >>Growth and Characterization of ZnO Nanocrystals
2013 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The understanding of surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. Therefore, it is important to understand the fundamental surface properties in order to use NCs efficiently in applications. In the work reported in this thesis ZnO NCs were studied.

At MAX-lab in Lund, synchrotron radiation based Spectroscopic Photoemission and Low Energy Electron Microscopy (SPELEEM) and X-ray Photoelectron Spectroscopy (XPS) were used. At Karlstad University characterization was done using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Scanning Tunnelling Microscopy (STM), Auger Electron Spectroscopy (AES), and XPS.

The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. The conditions for distribution of ZnO NCs were determined to be beneficial when using ethanol as the solvent for ultrasonically treated dispersions. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs.

Flat ZnO NCs with predominantly polar surfaces were grown using a rapid microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms.

Abstract [en]

Baksidestext

The understanding of the surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. In the work in this thesis ZnO NCs were studied.

The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs.

Flat ZnO NCs with predominantly polar surfaces were grown using a microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms.

Ort, förlag, år, upplaga, sidor
Karlstad: Karlstads universitet, 2013. s. 56
Serie
Karlstad University Studies, ISSN 1403-8099 ; 2013:26
Nyckelord
ZnO, Nanocrystals, Surface physics, XPS, SEM, AES, AFM, STM
Nationell ämneskategori
Nanoteknik Den kondenserade materiens fysik
Forskningsämne
Fysik
Identifikatorer
urn:nbn:se:kau:diva-27156 (URN)978-91-7063-503-8 (ISBN)
Disputation
2013-06-14, 21A 342, Karlstad University, Karlstad, 13:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2013-05-23 Skapad: 2013-05-02 Senast uppdaterad: 2013-05-23Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Personposter BETA

Ericsson, LeifMagnusson, Kjell

Sök vidare i DiVA

Av författaren/redaktören
Ericsson, LeifMagnusson, Kjell
Av organisationen
Institutionen för ingenjörsvetenskap och fysik
Den kondenserade materiens fysikNanoteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 217 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf