Trions in ZnO quantum wells and verification of the valence band ordering
Abstract
Unambiguous evidence of negatively charged excitons (trions) in ZnO/(Zn,Mg)O quantum wells is provided by magneto-optical studies. Distinct features are detected both in transmission and photoluminescence with a spectral width clearly below the trion binding energy of 13 meV. The magnetic-field-induced circular polarization of the trionic absorption lines due to thermalization of the two-dimensional electron gas is used to evaluate the controversially discussed ordering of the valence bands. The Γ7 symmetry found for the uppermost band in the quantum well is in agreement with the widely accepted situation for bulk ZnO.
- Publication:
-
Physical Review B
- Pub Date:
- January 2012
- DOI:
- 10.1103/PhysRevB.85.041307
- Bibcode:
- 2012PhRvB..85d1307P
- Keywords:
-
- 71.35.Pq;
- 73.21.Fg;
- 78.66.Hf;
- Charged excitons;
- Quantum wells;
- II-VI semiconductors