Spectroscopic study of nanocrystalline TiO2 thin films grown by atomic layer deposition

Citation
A. Suisalu et al., Spectroscopic study of nanocrystalline TiO2 thin films grown by atomic layer deposition, THIN SOL FI, 336(1-2), 1998, pp. 295-298
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
THIN SOLID FILMS
ISSN journal
00406090 → ACNP
Volume
336
Issue
1-2
Year of publication
1998
Pages
295 - 298
Database
ISI
SICI code
0040-6090(199812)336:1-2<295:SSONTT>2.0.ZU;2-M
Abstract
Photoluminescence characteristics of nanocrystalline TiO2 films grown by at omic layer deposition were studied. In dependence of growth conditions the films consisted of anatase, rutile and TiO2-II phases. A broad band and two sharp peaks were observed in the photoluminescence spectra measured under continuous-wave Ar+ laser excitation at temperatures 5-165 K. At 5 K the ma ximum of the broad band was at 2.24 eV in the anatase films, and at 2.37-2. 40 eV in the rutile and TiO2-II films. The intensity of sharp Lines peaking at 3.31 and 3.37 eV depended on the crystal structure of the films and inc reased significantly after X-ray irradiation. The temperature dependence an d decay times of different emission bands were also investigated. The data obtained allowed a defect-trapped-exciton interpretation of the sharp peaks although the free-exciton origin of the 3.31 eV peak could still be argued . The broad-band emission at 2.24-2.40 eV was obviously due to self-trapped exciton recombination. (C) 1998 Elsevier Science S.A. All rights reserved.