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

Abstract
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.