Excited states ofFe3+in GaN

R. Heitz, P. Maxim, L. Eckey, P. Thurian, A. Hoffmann, I. Broser, K. Pressel, B. K. Meyer
1997 Physical Review B (Condensed Matter)  
We report a comprehensive photoluminescence excitation ͑PLE͒ investigation of the deep iron acceptor in hexagonal GaN. PLE spectra of the Fe 3ϩ ͓ 4 T 1 ͑G͒-6 A 1 ͑S͔͒ luminescence in semi-insulating GaN samples reveal intracenter excitation processes via excited states of the Fe 3ϩ center. Zero-phonon lines resolved around 2.01 and at 2.731 eV are attributed to the 6 A 1 ͑S)-4 T 2 (G) and the 6 A 1 (S)-4 E(G) transition, respectively. A steplike excitation structure on the low-energy onset of
more » ... w-energy onset of the Fe 3ϩ/2ϩ charge-transfer band is attributed to the formation of a ͑Fe 3ϩ ,e,h͒ complex at 2.888 eV. We estimate a binding energy of 280 meV locating the deep Fe 3ϩ/2ϩ acceptor level 3.17 eV above the valence-band maximum. In n-type GaN samples the Fe 3ϩ luminescence is excited by hole-transfer processes. The experimental results indicate that the internal reference rule fails for the GaN/GaAs heterostructure.
doi:10.1103/physrevb.55.4382 fatcat:kx4ej4y2ojen3i666en3zqcjzm