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EPR detection of Mg acceptor in InGaN Mary Ellen Zvanut, University of Alabama at Birmingham, DMR 1006163. Incorporation of In increases conductivity. The addition of Mg to GaN creates a p-type semiconductor used in LED’s and detectors
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EPR detection of Mg acceptor in InGaNMary Ellen Zvanut, University of Alabama at Birmingham, DMR 1006163 Incorporation of In increases conductivity The addition of Mg to GaN creates a p-type semiconductor used in LED’s and detectors The presence of indium changes the color emitted or detected cimewww.epfl.ch Gallium Indium Nitrogen We show (right) that the conductivity (σ) and source of that conductivity (holes) increases with increasing Indium incorporation In0.02Ga0.98N In0.11Ga0.89N 0.8/ohm-cm σ = 0.5 /ohm-cm This is good and expected We also show that the source of the conductivity and holes as reflected by the intensity of the Mg-related EPR signal (MgEPR) DECREASES with indium incorporation This is curious and unexpected The origin of the beneficial hole production obtained from InGaN is NOT merely due to the Mg acceptors seen in p-type GaN MgEPR (□) and hole concentrations ( ) The dashed line represents the EPR signal detection limit.
Understanding the Mg acceptor in nitride filmsMary Ellen Zvanut, University of Alabama at Birmingham, DMR 1006163 Several measurements methods are used to attack the questions that arise from our EPR studies The project is providing students with exposure to several experimental techniques and interactions with national laboratories. Collaborations: Dan D. Koleske, Andy Allerman – Sandia National Laboratory: sample design and growth; technical guidance Stephen Hill – National High Magnetic Field Laboratory: multifrequency EPR to determine the source of the linewidth M. E. Zvanut, Ustun R. Sunay, J. Dashdorj, W. R. Willoughby and A. A. Allerman, "Mg-hydrogen interaction in AlGaN alloys", Proc. SPIE 8262, 82620L (2012). M.E. Zvanut, W.R. Willoughby, D.D.Koleske, “Source of holes in InGaN films”, Appl. Phys. Lett., submitted, Aug. 2012. Four Point Probe current-voltage Optical Absorption Supporting Techniques learned by sudents at UAB Raman Spectroscopy X-ray diffraction