Resonant photoemission of rare earth doped GaN thin films S.R. McHale, J.W. McClory, J.C. Petrosky, J. Wu, R. Palai, Ya.B. Losovyj and P.A. Dowben Eur. Phys. J. Appl. Phys., 56 1 (2011) 11301 Published online: 28 September 2011 DOI: 10.1051/epjap/2011110235