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Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments

Hydrothermally grown rutile TiO(2) nanowires are intrinsically full of lattice defects, especially oxygen vacancies. These vacancies have a significant influence on the structural and electronic properties of the nanowires. In this study, we report a post-growth heat treatment in different environme...

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Detalles Bibliográficos
Autores principales: Folger, Alena, Kalb, Julian, Schmidt-Mende, Lukas, Scheu, Christina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666454/
https://www.ncbi.nlm.nih.gov/pubmed/28946626
http://dx.doi.org/10.3390/nano7100289
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author Folger, Alena
Kalb, Julian
Schmidt-Mende, Lukas
Scheu, Christina
author_facet Folger, Alena
Kalb, Julian
Schmidt-Mende, Lukas
Scheu, Christina
author_sort Folger, Alena
collection PubMed
description Hydrothermally grown rutile TiO(2) nanowires are intrinsically full of lattice defects, especially oxygen vacancies. These vacancies have a significant influence on the structural and electronic properties of the nanowires. In this study, we report a post-growth heat treatment in different environments that allows control of the distribution of these defects inside the nanowire, and thus gives direct access to tuning of the properties of rutile TiO(2) nanowires. A detailed transmission electron microscopy study is used to analyze the structural changes inside the nanowires which are correlated to the measured optical and electrical properties. The highly defective as-grown nanowire arrays have a white appearance and show typical semiconducting properties with n-type conductivity, which is related to the high density of oxygen vacancies. Heat treatment in air atmosphere leads to a vacancy condensation and results in nanowires which possess insulating properties, whereas heat treatment in N(2) atmosphere leads to nanowire arrays that appear black and show almost metal-like conductivity. We link this high conductivity to a TiO(2−x) shell which forms during the annealing process due to the slightly reducing N(2) environment.
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spelling pubmed-56664542017-11-09 Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments Folger, Alena Kalb, Julian Schmidt-Mende, Lukas Scheu, Christina Nanomaterials (Basel) Article Hydrothermally grown rutile TiO(2) nanowires are intrinsically full of lattice defects, especially oxygen vacancies. These vacancies have a significant influence on the structural and electronic properties of the nanowires. In this study, we report a post-growth heat treatment in different environments that allows control of the distribution of these defects inside the nanowire, and thus gives direct access to tuning of the properties of rutile TiO(2) nanowires. A detailed transmission electron microscopy study is used to analyze the structural changes inside the nanowires which are correlated to the measured optical and electrical properties. The highly defective as-grown nanowire arrays have a white appearance and show typical semiconducting properties with n-type conductivity, which is related to the high density of oxygen vacancies. Heat treatment in air atmosphere leads to a vacancy condensation and results in nanowires which possess insulating properties, whereas heat treatment in N(2) atmosphere leads to nanowire arrays that appear black and show almost metal-like conductivity. We link this high conductivity to a TiO(2−x) shell which forms during the annealing process due to the slightly reducing N(2) environment. MDPI 2017-09-23 /pmc/articles/PMC5666454/ /pubmed/28946626 http://dx.doi.org/10.3390/nano7100289 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Folger, Alena
Kalb, Julian
Schmidt-Mende, Lukas
Scheu, Christina
Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title_full Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title_fullStr Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title_full_unstemmed Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title_short Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments
title_sort tuning the electronic conductivity in hydrothermally grown rutile tio(2) nanowires: effect of heat treatment in different environments
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666454/
https://www.ncbi.nlm.nih.gov/pubmed/28946626
http://dx.doi.org/10.3390/nano7100289
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