Optical and microstructural properties of N- and Ga-polarity GaN

A. Bell, J. L. Smit, R. Liu, J. Mei, Fernando Ponce, H. M. Ng, A. Chowdhury, N. G. Weimann

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


The effect of polarity on the optical and microstructural properties of GaN is presented. A sample with adjacent domains of Ga- and N-polarity material was grown by varying the nucleation layer. This allows a unique opportunity to study the two different polarities under controlled conditions. We found that the N-polarity material has a much lower dislocation density than the Ga-polarity material. The N-polarity material contains voids that are not present in the Ga-polarity region. The surface roughness of the N-polarity material appears to be caused by Ga-polarity inversion domains which lead the growth. A cathodoluminescence study showed that the N-polarity material is much brighter than the Ga-polarity material, suggesting a higher donor concentration, probably due to increased impurity incorporation in the [0001̄] growth direction or possibly due to an increase in intrinsic point defects. There is also evidence that the N-polarity region contains two types of material, one is flat and can be etched, the other has an inclined facet and does not etch.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsH.M. Ng, M. Wraback, K. Hiramatsu, N. Grandjean
Number of pages6
StatePublished - 2003
EventGaN and Related Alloys - 2003 - Boston, MA, United States
Duration: Dec 1 2003Dec 5 2003


OtherGaN and Related Alloys - 2003
Country/TerritoryUnited States
CityBoston, MA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials


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