Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 66: GaN: Preparation and characterization of rods and wires
HL 66.7: Vortrag
Mittwoch, 13. März 2013, 18:30–18:45, H15
Catalyst-free, self-organized growth of GaN nanorods on r-plane and c-plane sapphire with MBE and MOVPE — •Julian Stöver, Timo Aschenbrenner, Stephan Figge, Gerd Kunert, and Detlef Hommel — Institute of Solid State Physics, Epitaxy, University of Bremen, Otto-Hahn-Allee NW1, 28359 Bremen
High-quality GaN nanorods can be grown on r-plane sapphire by a combination of MOVPE and MBE. The r-plane sapphire was nitridated in a MOVPE reactor at 1050 ∘C, which leads to a change in surface morphology, e.g. small AlN islands are visible. The nanorod growth is carried out in MBE, in which the AlN islands act as nucleation centers. The nanorod density can be controlled by GaN overgrowth in MOVPE after the nitridation process. A sharp D0X emission in µ-PL measurements indicates the high crystalline quality [Aschenbrenner et al., Nanotechnology 20(7), 075604 (2009)]. Assigning the growth parameters on c-plane sapphire will not provide changes in the morphology. Due to the missing nucleation centers, nanorod growth did not take place. With a higher growth temperature of 1270 ∘C, changes in the surface morphology are achieved. AlN islands with a diameter of 35 nm and a density of 50 islands/µ m2 are provided. Similar to the growth on r-plane sapphire, GaN is deposited after the nitridation. The GaN provides a partial coverage with hexagonal structures. The structures itself and the space in between have diameters of 450−500 nm.
Differences in the growth on r-plane and c-plane sapphire will be presented as well as detailed analyses of the structures grown on c-plane sapphire.