Excitons and rare-earth ions in CsCdBr3


Heber J., Demirbilek R. , Nikitin S.

JOURNAL OF ALLOYS AND COMPOUNDS, cilt.380, ss.50-54, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 380
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1016/j.jallcom.2004.03.021
  • Dergi Adı: JOURNAL OF ALLOYS AND COMPOUNDS
  • Sayfa Sayıları: ss.50-54

Özet

CsCdBr3 has a quasi-linear crystal structure. It consists of covalently bound [CdBr](6)(4-) chains separated by chains of Cs+ ions. The trivalent rare-earth (RE) ions substitute for divalent Cd ions forming predominantly pair centers of the type RE3+-(Cd vacancy)-RE3+. A minority of RE ions forms "single-ion" centers with more distant charge compensation. The electronic structure around the band gap is determined by the [CdBr](6)(4-) octahedra. The lowest excitonic states of the lattice are charge-transfer states of these octahedra. At low temperatures they form self-trapped excitons which become mobile around 80 K.