Photoluminescence and excitation spectroscopy of the 1.5 μm Er-related band in MBE-grown GaN layers

The infrared photoluminescence at 1.5 m due to the I-4(13/2) --> I-4(15/2) transition of Er3+ ions has been investigated for GaN:Er3+ layers grown by MBE. Low temperature high resolution measurements performed under continuous illumination at the wavelength lambda(exc) = 532 nm, resonant to one of the intra-4f-shell transitions, revealed that the 1.5 mum band consists of up to eight individual spectral components. In excitation spectroscopy, a temperature dependence splitting of resonant bands was observed. On the basis of these experimental results, a possible multiplicity of optically active centers formed by Er doping in GaN layers is discussed. (C) 2004 Elsevier Ltd. All rights reserved.