Schwingungs- und elektronenspektroskopische Untersuchungen an reinen und wasserstoffbedeckten III-Nitridoberflächen

In this thesis clean GaN{0001} as well as AlGaN(0001) surfaces were characterized by high-resolution electron energy-loss spectroscopy (HREELS) and electron spectroscopic means. Moreover, the interaction of hydrogen with GaN{0001} surfaces of both polarities was investigated. At clean GaN surfaces the vibrational and electronic properties were determined, surface cleaning procedures and thermal decomposition were examined. By means of HREELS the energy of the Fuchs-Kliewer (FK)-phonon was determined as 86.8 meV. At Ga-polar surfaces a gap state at 2.7 eV was found. Atomic hydrogen was found to bind to both N and Ga. Deuteration of the surface delivered clear evidence for this behaviour and, thus, resolved a discrepancy published in the literature. Photoemission measurements confirmed this finding. The properties of AlGaN surfaces were investigated as a function of their composition. Over the whole composition range no evidence for a negative electron affinity was found. The FK phonons of AlGaN show a one-mode behaviour.


Citation style:
Could not load citation form.


Use and reproduction:
All rights reserved