Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MM: Fachverband Metall- und Materialphysik

MM 15: Poster Session

MM 15.79: Poster

Montag, 11. März 2013, 18:00–20:00, Poster E

TEM dark-field characterization of anti phase domain boundaries in GaAs on Ge — •Lukas Nattermann, Tatjana Wegele, and Kerstin Volz — Structure and Technology Research Laboratory, Materials Science Center and Faculty of Physics Philipps-Universität Marburg, Germany

The use of GaAs on Ge in multijunction solar cells requires a high crystal quality and a defect-free GaAs/Ge interface. For the characterization of the GaAs-layer and the GaAs on Ge boundary we used transmission electron microscopy (TEM). Additionally we compared GaAs on Ge to GaP on Si with respect to the anti phase domain (APDs) boundaries. In order to investigate the influence of such growth-parameters as temperature and the atom types in the monolayer between GaAs and Ge, three MOVPE (metal organic vapour phase epitaxy)-grown GaAs/Ge - samples were examined by using the TEM dark-field (DF)-technique. To verify APDs with the help of contrast reversal we used the (002)- and (00-2)-DF-reflections. We study specimens in three different zone axes, [001], [110] and [1-10], to get an idea of the three dimensional shape of the anti phase domains. We can show the difference of the shape of APDs in GaAs on Ge and GaP on Si and the influence of the insufficient pretreatment of the Ge-substrate. Moreover we determine the directions of the propagation planes of the APD-boundaries and analyze the size of the APDs.