Electrical and Optical Properties of Semi-insulating GaN

Document Type


Publication Date



Molecular-beam-epitaxial (MBE) GaN layers can be made semi-insulating (SI) by using a high N flux during growth. For growth at low N flux, the samples have high concentrations (>10(18) cm(-3)) of shallow donors and shallow accepters, and also contain a deep center producing a yellow band (2.2 eV) in photoluminescence (PL). For growth at high N flux, the PL lines attributed to shallow accepters and the yellow band disappear, and the only remaining lines are due to the ground and excited states of the free-exciton A and B bands. The SI material does not produce a measurable Hall effect: and the conduction mechanism is assigned to hopping between deep defects. Using arguments from stoichiometry and theory, we tentatively assign the shallow donors, shallow accepters, and deep center to the N vacancy, Ga-antisite/Ga-vacancy complex, and Ga antisite, respectively. (C) 1997 Elsevier Science S.A.


This paper was presented at the 3rd International Workshop on Expert Evaluation and Control of Compound Semiconductor Materials and Technology, May 12-15, 1996 in Freiburg, Germany.



Find in your library

Off-Campus WSU Users