Variation of band bending at the surface of Mg-doped InGaN: evidence of p-type conductivity across the composition range
King, P. D. C., Veal, T. D. (Tim D.), Jefferson, P. H., McConville, C. F. (Chris F.), Lu, Hai and Schaff, W. J.. (2007) Variation of band bending at the surface of Mg-doped InGaN: evidence of p-type conductivity across the composition range. Physical Review B, 75 (11). Article: 115312. ISSN 1098-0121Full text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevB.75.115312
The variation of band bending as a function of composition at oxidized (0001) surfaces of Mg-doped InxGa1-xN is investigated using x-ray photoelectron spectroscopy. Distinctly different trends in barrier height are seen for the Mg-doped compared to undoped alloys, which is explained in terms of Fermi-level pinning at the surface and virtual gap states. Solutions of Poisson's equation within the modified Thomas-Fermi approximation are used to model the band bending and corresponding variation of carrier concentration with depth below the surface. A transition from a surface inversion layer for In-rich alloys to a surface hole depletion layer for Ga-rich alloys occurs at x approximate to 0.49. The trend in barrier height, calculated space-charge profiles, and difference of barrier height for undoped and Mg-doped InN indicate that Mg doping induces bulk p-type conductivity across the entire composition range.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Physical Review B|
|Publisher:||American Physical Society|
|Official Date:||March 2007|
|Number of Pages:||7|
|Page Range:||Article: 115312|
|Access rights to Published version:||Restricted or Subscription Access|
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