1. Laboratory of Semiconductor Materials
2. KTH
3. 164 40 Kista, Sweden
4. Optoelectronics Research Centre
5. Tampere University of Technology
6. FIN-33101 Tampere, Finland
7. Thin Film Physics Division
8. Department of Physics (IFM)
9. Linköping University
10. S-581 83 Linköping, Sweden