Epitaxial electrodeposition of Fe onto GaAs nanowires.

Fe contacts with thickness ranging from 50 nanometers to 100 nanometers were selectively fabricated onto Au catalysed, Te-doped n-GaAs (111) nanowires via galvanostatic electrodeposition. An insulating polymer (SU-8) was used to fill in between the nanowires preventing deposition directly onto the GaAs substrate. Scanning transmission electron microscopy investigations combined with energy-dispersive X-ray analysis verified the existence of single-crystalline, epitaxial Fe/GaAs (110) on the sidewalls of typical nanowires. Electrical barrier heights (0.53 ± 0.02 eV) and ideality factors (1.7 to 1.9) were obtained from current-voltage measurements of individual nanowires in a scanning electron microscope.