Deep level defects in n-type GaN grown by molecular beam epitaxy

Deep-level transient spectroscopy has been used to characterize electronic defects in n-type GaN grown by reactive molecular-beam epitaxy. Five deep-level electronic defects were observed, with activation energies E-1=0.234+/-0.006, E-2=0.578+/-0.006, E-3=0.657+/-0.031, E-4=0.961+/-0.026, and E-5=0.240+/-0.012 eV. Among these, the levels labeled E-1, E-2, and E-3 are interpreted as corresponding to deep levels previously reported in n-GaN grown by both hydride vapor-phase epitaxy and metal organic chemical vapor deposition. Levels E-4 and E-5 do not correspond to any previously reported defect levels, and are characterized for the first time in our studies. (C) 1998 American Institute of Physics. [S0003-6951(98)02910-6].