Excitation Wavelength- and Medium-Dependent Photoluminescence of Reduced Nanostructured TiO2 Films
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F19%3A73594939" target="_blank" >RIV/61989592:15310/19:73594939 - isvavai.cz</a>
Result on the web
<a href="https://pubs.acs.org/doi/10.1021/acs.jpcc.9b01727" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpcc.9b01727</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpcc.9b01727" target="_blank" >10.1021/acs.jpcc.9b01727</a>
Alternative languages
Result language
angličtina
Original language name
Excitation Wavelength- and Medium-Dependent Photoluminescence of Reduced Nanostructured TiO2 Films
Original language description
The performance of TiO2 nanomaterials in solar energy conversion applications can be tuned by means of thermal treatments in reducing atmospheres, which introduce defects (such as oxygen vacancies), allowing, for instance, a better charge transport or a higher photocatalytic activity. The characterization of these defects and the understanding of their role are pivotal to carefully engineer the properties of TiO2, and among various methods, they have been addressed by photoluminescence (PL) spectroscopy. A definitive framework to describe the PL properties of TiO2, however, is still lacking. In this work, we report on the PL of nanostructured anatase TiO2 thin films, annealed in different atmospheres (oxidizing and reducing), and consider the effects of different excitation energies and different surrounding media on their PL spectra. A broad PL signal centered around 1.8-2.0 eV is found for all the films with UV excitation in air and in vacuum, while the same measurements in ethanol lead to a blueshift and to intensity changes in the spectra. On the other hand, measurements with different sub-bandgap excitations show PL peaking at 1.8 eV, with an intensity trend only dependent on the thermal treatment and not on the surrounding medium. The results of PL spectroscopy, together with electron paramagnetic resonance spectroscopy, suggest the critical role of oxygen vacancies and Ti3+ ions as radiative recombination centers. The complex relationship between thermal treatments and PL data in the explored conditions is discussed, suggesting the importance of such investigations for a deeper understanding on the relationship between defects in TiO2 and photoactivity.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
<a href="/en/project/EF15_003%2F0000416" target="_blank" >EF15_003/0000416: Advanced Hybrid Nanostructures for Renewable Energy Applications</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Physical Chemistry C
ISSN
1932-7447
e-ISSN
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Volume of the periodical
123
Issue of the periodical within the volume
17
Country of publishing house
US - UNITED STATES
Number of pages
12
Pages from-to
11292-11303
UT code for WoS article
000466988600062
EID of the result in the Scopus database
2-s2.0-85065318607