Morphological and Electrical Characterization of GaAs Nanowires

GaAs nanowires were grown using metal organic chemical vapor deposition (MOCVD) system at low pressure reactor chamber. The growth follows the vapor-liquid solid mechanism by applying nanoparticle gold colloid on the (111)B GaAs substrate. The growth process were done at temperatures ranging from 380 to 600 deg C. The prepared samples were characterized using scanning electron microscopy, SEM and conductive atomic force microscopy, CAFM. It shows that GaAs nanowires grown at lower temperatures were rod-shaped and increasingly tapered with increasing growth temperature. Electrical measurements on individual GaAs nanowires indicate ohmic characteristic for samples prepared at 440 deg C, while oscillation current occured for GaAs nanowire with higher growth temperatures. These properties of GaAs nanowires can be guided to provide an opportunity for direct integration of high performance III-V semiconductor nanoscale devices.