1. Direct experimental determination of the spontaneous polarization of GaN
- Author
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Lähnemann, Jonas, Brandt, Oliver, Jahn, Uwe, Pfüller, Carsten, Roder, Claudia, Dogan, Pinar, Grosse, Frank, Belabbes, Abderrezak, Bechstedt, Friedhelm, Trampert, Achim, and Geelhaar, Lutz
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We present a universal approach for determining the spontaneous polarization Psp of a wurtzite semiconductor from the emission energies of excitons bound to the different types of stacking faults in these crystals. Employing micro-photoluminescence and cathodoluminescence spectroscopy, we observe emission lines from the intrinsic and extrinsic stacking faults in strain-free GaN micro-crystals. By treating the polarization sheet charges associated with these stacking faults as a plate capacitor, Psp can be obtained from the observed transition energies with no additional assumptions. Self-consistent Poisson-Schroedinger calculations, aided by the microscopic electrostatic potential computed using density-functional theory, lead to nearly identical values for Psp. Our recommended value for Psp of GaN is -0.022+/-0.007 C/m^{2}., Comment: 5 pages, 5 figures
- Published
- 2012
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