| AVS 54th International Symposium | |
| Surface Science | Monday Sessions |
| Session SS2-MoA |
| Session: | Electronic and Vibrational Structure |
| Presenter: | K.E. Smith, Boston University |
| Authors: | K.E. Smith, Boston University L. Colakerol, Boston University T. Learmonth, Boston University P.A. Glans, Boston University L.F.J. Piper, Boston University A. Fedorov, Lawrence Berkeley National Laboratory T.D. Veal, University of Warwick, UK C.F. McConville, University of Warwick, UK S. Healy, University College Cork, Ireland E.P. O'Reilly, University College Cork, Ireland T.C. Chen, Boston University T.D. Moustakas, Boston University |
| Correspondent: | Click to Email |
The valence and conduction band electronic structure in InN thin films has been measured using high resolution Angle Resolved Photoemission Spectroscopy (ARPES). InN exhibits an accumulation layer near the film surface, and our ARPES measurements reveal that the conduction band electrons in the accumulation layer exist in intrinsic quantum well states.1 We also used ARPES to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level. The energy of the Fermi level, and the size of the Fermi surface for these quantum well states could be controlled by varying the method of surface preparation. Furthermore, a minimum is observed in the dispersion of the top of the valence band, with the highest measured valence band having an electron-like dispersion at the Brillouin zone center, which is unexpected in the context of earlier measurements and calculations. Valence band holes see a quantum barrier near the surface, and a theoretical analysis using a k.p approach of the influence of this barrier indicates that the anomalous dispersion is most likely due to a negative crystal field splitting in InN, contrary to previous expectations. This work was supported in part by the DOE under RF-06-PRD-001 (subcontract from University of Nevada, Las Vegas), by the NSF under grant number DMR-0311792, and by Science Foundation Ireland. The ALS is supported by the DOE, Materials Sciences Division under contract no. DE-AC03-76SF00098.
1 1. L. Colakerol, T.D. Veal, H.-K. Jeong, L. Plukinski, A. DeMasi, S. Wang, Y. Zhang, L.F.J. Piper, P.H. Jefferson, A. Fedorov, T.C. Chen, T. D. Moustakas, C.F. McConville, and K.E. Smith, Phys. Rev. Lett. 97, 237601 (2006).