TY - JOUR
T1 - Influence of laser pulse regime on the structure and optical properties of TiO2 nanolayers
AU - Peñaloza-Mendoza, Y.
AU - Alvira, F. C.
AU - Caballero-Briones, F.
AU - Guarneros-Aguilar, C.
AU - Ponce, L.
N1 - Publisher Copyright:
© 2018 IOP Publishing Ltd.
PY - 2018/12
Y1 - 2018/12
N2 - TiO2 films were deposited onto glass substrates by pulsed laser deposition (PLD) in high vacuum under monopulse and multipulse excitation. After deposition, a thermal treatment on air atmosphere was done to promote crystallization. Films were studied by x-ray diffraction, energy dispersive spectroscopy, scanning electron, atomic force microscopy, UV-vis spectroscopy, and ellipsometry. After air annealing, films gain a different amount of oxygen: TiO1.9 in multipulse regime versus TiO1.7 in the monopulse one. Splashing is observed in both regimes although in the multipulse mode greater particles are found, that derived in a less compact film after annealing which could be the cause of the better oxygen diffusion. The optical band gap of the film prepared with monopulse excitation is 3.09 eV. This value increased to 3.34 eV with annealing, corresponding to that of anatase. The film made with multipulses has an Eg = 3.12 eV which was invariant upon annealing. The difference in the properties of the films grown in the different regimes was attributed to the re-excitation of the plasma during the ablation process in the multipulse ablation that leads to an increased splashing density and thereafter a less compact film and the presence of off-stoichiometry inclusions within the film bulk.
AB - TiO2 films were deposited onto glass substrates by pulsed laser deposition (PLD) in high vacuum under monopulse and multipulse excitation. After deposition, a thermal treatment on air atmosphere was done to promote crystallization. Films were studied by x-ray diffraction, energy dispersive spectroscopy, scanning electron, atomic force microscopy, UV-vis spectroscopy, and ellipsometry. After air annealing, films gain a different amount of oxygen: TiO1.9 in multipulse regime versus TiO1.7 in the monopulse one. Splashing is observed in both regimes although in the multipulse mode greater particles are found, that derived in a less compact film after annealing which could be the cause of the better oxygen diffusion. The optical band gap of the film prepared with monopulse excitation is 3.09 eV. This value increased to 3.34 eV with annealing, corresponding to that of anatase. The film made with multipulses has an Eg = 3.12 eV which was invariant upon annealing. The difference in the properties of the films grown in the different regimes was attributed to the re-excitation of the plasma during the ablation process in the multipulse ablation that leads to an increased splashing density and thereafter a less compact film and the presence of off-stoichiometry inclusions within the film bulk.
KW - TiO
KW - TiO air annealing
KW - TiO optical properties
KW - TiO structure
KW - multipulse and monopulse regimes
KW - pulsed laser deposition
UR - http://www.scopus.com/inward/record.url?scp=85059459310&partnerID=8YFLogxK
U2 - 10.1088/2053-1591/aae2e5
DO - 10.1088/2053-1591/aae2e5
M3 - Artículo
SN - 2053-1591
VL - 5
JO - Materials Research Express
JF - Materials Research Express
IS - 12
M1 - 125022
ER -