SELF-ORGANIZED GROWTH OF GAAS INAS HETEROSTRUCTURE NANOCYLINDERS BY ORGANOMETALLIC VAPOR-PHASE EPITAXY/

Free-standing GaAs/InAs heterostructure wires as thin as 20 nm and as long as 1 mu m have been formed by vapor-liquid-solid (VLS) growth dur ing organometallic vapor phase epitaxy. The grown wires were analyzed by transmission electron microscopy, which revealed that the crystal s tructure of the GaAs portion coincides with that of zincblende, and th e InAs portion coincides with that of wurtzite. The atomic composition along the heterojunction was also measured by energy dispersive X-ray analysis. The composition changes within a width of 5 nm at the heter ojunction interface. The InAs/GaAs wires show a photoluminescence peak around 1.5 eV at 14 K, which indicates significant improvement in cry stal quality over conventional GaAs/InAs layer structures.