Quantum chemical modelling of electron polarons and excitons in ABO(3) perovskites

Autor(en): Kotomin, EA
Eglitis, RI
Borstel, G
Stichwörter: CORUNDUM CRYSTALS; DOPED KTAO3; F-CENTERS; FIRST-PRINCIPLES; HARTREE-FOCK CALCULATIONS; INDO METHOD; KNBO3; OPTICAL-PROPERTIES; PHOTOLUMINESCENCE; Physics; Physics, Condensed Matter; SEMIEMPIRICAL CALCULATIONS
Erscheinungsdatum: 2000
Herausgeber: IOP PUBLISHING LTD
Journal: JOURNAL OF PHYSICS-CONDENSED MATTER
Volumen: 12
Ausgabe: 35
Startseite: L557-L562
Zusammenfassung: 
Quantum chemical calculations using the intermediate neglect of the differential overlap (INDO) method, combined with the large unit cell periodic model argue for an existence of the self-trapped electrons in KNbO3 and KTaO3 perovskite crystals. An electron in the ground state occupies predominantly t(2g) orbital of a Nb4+ ion. Its orbital degeneracy is lifted by a combination of the breathing and Jahn-Teller modes where four nearest equatorial O atoms are displaced outwards and two oxygens shift inwards along the z axis. Triplet exciton is shown to be in a good approximation of a pair of nearest Jahn-Teller electron and hole polarons (a bipolaron) which is very likely responsible for the `green' luminescence observed in these crystals.
ISSN: 09538984
DOI: 10.1088/0953-8984/12/35/101

Show full item record

Page view(s)

2
Last Week
0
Last month
0
checked on Feb 26, 2024

Google ScholarTM

Check

Altmetric