Growth of embedded ErAs nanorods on (4 1 1 )A and (4 1 1 )B GaAs by molecular beam epitaxy

摘要

The low solubility of Er in GaAs results in the formation of ErAs nanostructures when GaAs is grown with 5-6 at% Er/Ga ratio by molecular beam epitaxy on GaAs surfaces. For growth on the (4 1 1 )A GaAs surface, cross-sectional scanning transmission electron microscopy images show the presence of ErAs nanorods embedded in a GaAs matrix extending along the [211] direction with a spacing of roughly 7 nm and a diameter of roughly 2 nm. Growth on the GaAs (411)B surface resulted in only nanoparticle formation. Variation of the polarized optical absorption with in-plane polarization angle is consistent with coupling to surface plasmon resonances of the semimetallic nanostructures.