Rare earth 4f hybridization with the GaN valence band

Authors

Lu Wang, University of Nebraska at Omaha
Wai-Ning Mei, University of Nebraska at OmahaFollow
S. R. McHale, Air Force Institute of Technology
J. W. McClory, Air Force Institute of Technology
J. C. Petrosky, Air Force Institute of Technology
J. Wu, University of Puerto Rico
R. Palai, University of Puerto Rico
Y. B. Losovyj, Louisiana State University at Baton Rouge
Peter A. Dowben, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2012

Citation

Semicond. Sci. Technol. 27 (2012) 115017 (7pp)

Comments

© 2012 IOP Publishing Ltd

This document is a U.S. government work and is not subject to copyright in the United States.

doi:10.1088/0268-1242/27/11/115017

Abstract

The placement of the Gd, Er and Yb 4f states within the GaN valence band has been explored by both experiment and theory. The 4d–4f photoemission resonances for various rare-earth(RE)-doped GaN thin films (RE = Gd, Er, Yb) provide an accurate depiction of the occupied 4f state placement within the GaN. The resonant photoemission show that the major Er and Gd RE 4f weight is at about 5–6 eV below the valence band maximum, similar to the 4f weights in the valence band of many other RE-doped semiconductors. For Yb, there is a very little resonant enhancement of the valence band of Yb-doped GaN, consistent with a large 4f^14-δ occupancy. The placement of the RE 4f levels is in qualitative agreement with theoretical expectations.