Optical properties of vanadium ions in ZnSe
G Goetz; U W Pohl; H -J Schulz; G Goetz; Fritz-Haber-Inst., Max-Planck-Gesellschaft, Berlin, Germany; U W Pohl; Fritz-Haber-Inst., Max-Planck-Gesellschaft, Berlin, Germany; H -J Schulz; Fritz-Haber-Inst., Max-Planck-Gesellschaft, Berlin, Germany
Журнал:
Journal of Physics: Condensed Matter
Дата:
1992-10-19
Аннотация:
The photoluminescence of intentionally vanadium-doped ZnSe crystals displays at low temperatures (T approximately=4 K) the emission of the V<sup>3+</sup> (d<sup>2</sup>), V<sup>2+</sup> (d<sup>3</sup>) and V<sup>+</sup> (d<sup>4</sup>) ions with different no-phonon structures at 5440, 4740 and 3640 cm<sup>-1</sup>, respectively. The excitation spectra of the V<sup>3+</sup> and V<sup>2+</sup> luminescence bands are investigated separately and exhibit structures of the respective spin-allowed as well as spin-forbidden internal transitions, which are largely in accordance with those of ZnS:V. The corresponding energy levels are approximated in a computation following the Tanabe-Sugano scheme. Furthermore, charge transfer processes at the luminescent centres are manifest in excitation, stimulation and transmission spectra. The vanadium ion proves to be an amphoteric impurity. Commencing from V<sup>2+</sup>, the state with neutral effective charge, light-induced transitions of donor and acceptor type are disclosed: V<sup>2+</sup> to or from V<sup>3+</sup>+e<sub>CB</sub><sup>-</sup> and V<sup>2+</sup> to or from V<sup>+</sup>+e<sub>VB</sub><sup>+</sup>.
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