Start of funding 01.07.2005

Characterization of defects and impurities in bulk AlN crystals

Prof. Dr. Albrecht Winnacker
Friedrich-Alexander-University of Erlangen-Nuremberg
Institute Materials for Electronics and Energy Technology

Prof. Dr. Eicke Weber
University of California, Berkeley
Department of Materials Science and Engineering



Aluminum nitride (AlN) is a promising substrate material to be employed e.g. in deep-UV optoelectronic and high-power microwave devices. Recently, the Erlangen university group described a process for the preparation of novel self-nucleated AlN bulk crystals. The aim of the project is to understand the nature of the facet-dependent impurity incorporation and point defect formation of such crystals. Both university parties will work in close cooperation to systematically investigate (i) AlN growth on facets having a different crystallographic type and (ii) the nature of the defects involved. Characterization will be carried out mainly in Berkeley including time-resolved photoluminescence, photoreflectance, optical absorption, Raman scattering, XBIC/EBIC, and EPR/ODMR techniques. Results will bring valuable hints for further optimization of AlN crystal growth, especially in regard to optical transmission, which is vital for UV optoelectronic applications