Quantitative determination of charge transfer parameters of photorefractive BaTiO3 : Rh from EPR-based defect studies
Autor(en): | Veber, C Meyer, M Schirmer, OF Kaczmarek, M |
Stichwörter: | ABSORPTION; BARIUM-TITANATE; CRYSTALS; Physics; Physics, Condensed Matter; RHODIUM; TRANSPORT PROCESSES | Erscheinungsdatum: | 2003 | Herausgeber: | IOP PUBLISHING LTD | Journal: | JOURNAL OF PHYSICS-CONDENSED MATTER | Volumen: | 15 | Ausgabe: | 3 | Startseite: | 415 | Seitenende: | 429 | Zusammenfassung: | Optical absorption bands can be used-as fingerprints of defects and their charge states in insulators and semiconductors. On the basis of the photochromicity usually shown by such materials, a method is introduced by which the optical bands are assigned to the defects and their charge states. It is based on simultaneous measurements of the light-induced changes of the optical absorption and of the corresponding EPR signals. Moreover, indirectly optical bands of EPR-silent defects can also be labelled in this way, strongly widening the scope of EPR based defect studies. We apply this method to the infrared-sensitive photorefractive system BaTiO3:Rh, where illumination leads to recharging among the valence states Rh5+, Rh4+ and Rh3+. The values of all parameters governing the charge transfers responsible are inferred from the magnitude of the absorption bands, the absolute determination of their absorption cross-sections and the kinetics of the absorption changes under illumination. In contrast to previous investigations, these parameters are deduced independently of photorefractive measurements. |
ISSN: | 09538984 | DOI: | 10.1088/0953-8984/15/3/307 |
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geprüft am 02.06.2024