Author/Authors :
Cremades، نويسنده , , A. and Piqueras، نويسنده , , Lisette J. C. Xavier and James J. Germida ، نويسنده , , C. and Monteiro، نويسنده , , T. and Pereira، نويسنده , , E. and Meyer، نويسنده , , B.K. and Hofmann، نويسنده , , D.M. and Fischer، نويسنده , , S.، نويسنده ,
Abstract :
GaN epitaxial layers have been investigated by cathodoluminescence (CL) in the scanning electron microscope (SEM). The most prominent feature of the spectra is a complex band at 2.2 eV, whose evolution with temperature and excitation density suggests emission mechanisms involving a deep center and donor-donor or donor-acceptor pairs. Time resolved photoluminescence (TRPL) measurements confirm the involvement of a deep center in the emission. CL images reveal that the centers responsible for this emission decorate grain boundaries. Emission bands at 2.87 eV and 1.31 eV have been also detected in the films.
