Investigation of the formation of the 2.8 eV luminescence band in p-type GaN : Mg

The stability of defects present in GaN:Mg has been investigated using phot oluminescence (PL) spectroscopy. The two dominant defect-related PL emissio n bands in p-type GaN were investigated, the blue band at 2.8 eV and the ul traviolet (UV) emission band at 3.27 eV. The intensity of the 3.27 eV PL ba nd increases with increasing resistivity, whereas the 2.8 eV PL band intens ity increases with a decrease in resistivity. The luminescence data is expl ained by a model whereby the concentration of luminescent centers depends o n the Fermi level position. The shallow donor responsible for the UV band i s attributed to hydrogen, whereas the deep donor defect responsible for the 2.8 eV band is attributed to a nitrogen vacancy complex. (C) 2000 American Institute of Physics. [S0003-6951(00)02121-5].