Temperature-dependent Hall-effect measurements in hydride vapor phase epitaxial GaN grown on sapphire can be well fitted over the temperature range 10–400 K by assuming a thin, degenerate n-type region at the GaN/sapphire interface. This degenerate interfacial region dominates the electrical properties below 30 K, but also significantly affects those properties even at 400 K, and can cause a second, deeper donor to falsely appear in the analysis. However, by using a two-layer Hall model, the bulk mobility and carrier concentration can be accurately ascertained.
Look, D. C.,
& Molnar, R. J.
(1997). Degenerate Layer at GaN/Sapphire Interface: Influence on Hall-Effect Measurements. Applied Physics Letters, 70 (25), 3377-3379.
Copyright © 1997, American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 70.25, and may be found at http://apl.aip.org/resource/1/applab/v70/i25/p3377_s1