Through the publication titled, “Assessment of deep level defects in m-plane GaN grown by metalorganic chemical vapor deposition”published in the Applied Physics Letters, EFRC scientists examine how spontaneous polarization and strain-induced piezoelectric polarization generate strong internal electric fields in gallium nitride (GaN).

Abstract: We report on deep level defect incorporation in n-type m-plane (10 0) GaN grown by metalorganic chemical vapor deposition (MOCVD) on built m-plane GaN substrates. Deep levels were observed at 2.85 eV and 3.31 eV relative to the conduction band minimum. While the energetic distribution of defect states for m-plane GaN was similar to the previous reports of n-type c-plane GaN grown by MOCVD, the deep level densities of the m-plane GaN were significantly lower. The comparatively low defect density in homoepitaxially grown m-plane GaN is attributed to reduced point defect incorporation. In addition to the absence of polarization fields, the low deep level density achieved by homoepitaxial growth on high quality bulk GaN substrates makes m-plane GaN highly attractive for opto-electronic devices.