6533b7d9fe1ef96bd126d57d
RESEARCH PRODUCT
Quantum chemical modelling of electron polarons and excitons in ABO3perovskites
G. BorstelRoberts I. EglitisEugene A. KotominEugene A. Kotominsubject
BipolaronCondensed matter physicsChemistryExcitonElectronCondensed Matter PhysicsPolaronQuantum chemistryMolecular physicsIonCondensed Matter::Materials ScienceCondensed Matter::Strongly Correlated ElectronsGeneral Materials ScienceGround statePerovskite (structure)description
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 t2g 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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2000-08-16 | Journal of Physics: Condensed Matter |