Selective area formation of GaN nanowires on GaN substrates by the use of amorphous Al O nucleation layer.

Examples are presented that application of amorphous Al O nucleation layer is an efficient way of controlling spatial distribution of GaN nanowires grown by plasma-assisted molecular beam epitaxy. On GaN/sapphire substrates Al O stripes induce formation of GaN nanowires while a compact GaN layer is formed outside the stripes. We show that the ratio of nanowire length h to the thickness of the compact layer d can be tailored by adjusting impinging gallium and nitrogen fluxes.

Determination of thermal conductivity of thin layers used as transparent contacts and antireflection coatings with a photothermal method.

A photothermal experiment with mirage detection was used to determine the thermal conductivity of various thin films deposited on semiconductor substrates. The first type consisted of conducting oxide films: ZnO and CdO deposited on GaSb:Te, while the other contained high dielectric constant HfO(2) layers on Si. All films were fabricated using a magnetron sputtering technique.