Mass transport growth and optical emission properties of hydride vapor phase epitaxy GaN

The optical emission properties of mass-transport regions of GaN grown by h ydride vapor phase epitaxy are studied by cathodoluminescence imaging and s pectroscopy. A strong donor-acceptor pair emission is observed from the mas s-transport regions. Spatially resolved cathodoluminescence reveals a stron g intensity contrast between the exciton and donor-acceptor bands from mass -transport and nontransport regions. Focused Auger electron and x-ray photo electron spectroscopies were employed to investigate the impurity incorpora tion in the different regions. A preferential moderate increase of residual impurity incorporation or redistribution in mass-transport regions is sugg ested to be responsible for the observed change of the dominant radiative m echanism. (C) 2001 American Institute of Physics.