Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/185307
COMPARTIR / EXPORTAR:
logo share SHARE BASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE

Invitar a revisión por pares abierta
Título

N and Cr (co-)Doping of TiO2 Thin Films Prepared by Reactive Magnetron Sputtering

AutorGago, Raúl CSIC ORCID; Prucnal, Slawomir; Palomares, F. Javier CSIC ORCID; Caretti, Ignacio CSIC ORCID; Redondo-Cubero, Andrés; Vinnichenko, Mykola
Fecha de publicación2015
EditorMaterials Research Society
CitaciónMRS Spring Meeting & Exhibit (2015)
ResumenThe photoactivity of TiO2 has been exploited in many applications ranging from photocatalysis, hydrogen production, pigments or solar cells [1]. However, optical absorption in TiO2 is mostly limited to the ultraviolet region of the solar spectrum (band-gap > 3 eV), triggering strong efforts to achieve visible-light (VISL) response by band-gap narrowing [1]. Non-metal (anion) doping seems to be a promising approach, as shown for the case of nitrogen (N) doped films [2]. However, it is unclear if the effective optical absorption of N-doped TiO2 is based on real band-gap narrowing or the formation of intragap localized states [3]. Recently, it has been argued that narrow-gap TiO2 would require heavy doping, relating VISL absorption to oxygen vacancies and color centers [4]. Another obstacle is the low thermodynamic solubility of dopants at substitutional sites [4]. This situation does not only compromise the effectiveness of band-gap narrowing but also provide recombination centers that are responsible for the loss of photogenerated electron-hole pairs [4]. A recent concept relies on N and Cr co-doping [5] to increase the solubility limit by non-compensated dopants where the opposite charge state of p- and n-type sites substantially enhances the thermodynamic kinetics of dopant pairs. In any case, a critical aspect of cation (co)doping relies in the introduction of large structural distortions in the host TiO2 matrix [4], needing processing or post-processing thermal treatments at moderate temperatures (~5000C). In this work, we address the production and characterization of TiO2 (co)doped films by magnetron sputtering. We also compare different thermal annealing methods for further dopant activation and enhancement/design of the structural order, with special attention to the influence of as-grown films. The potential of novel rapid thermal processing such as flash-lamp annealing is also explored. The electronic structure of as-grown and modified films is assessed by means of X-ray absorption fine-structure and photoelectron spectroscopy, which permits the analysis of either (nano)crystalline or disordered structures. The optical response is derived from spectroscopic ellipsometry and transmission measurements. Finally, the structural, optical and electronic properties are correlated with the photocatalytic response of the samples.
DescripciónPoster presented at the MRS Spring Meeting & Exhibit held on April 6-10th, 2015, on San Francisco (US). Symposium QQ: Plasma-Based Materials Science and Engineering.
URIhttp://hdl.handle.net/10261/185307
Aparece en las colecciones: (ICMM) Comunicaciones congresos




Ficheros en este ítem:
Fichero Descripción Tamaño Formato
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo

CORE Recommender

Page view(s)

216
checked on 28-mar-2024

Download(s)

30
checked on 28-mar-2024

Google ScholarTM

Check


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.