Heterostructures incorporated in one-dimensional semiconductor materials and devices

As an alternative to traditional top-down techniques for fabrication of one-dimensional devices we here report an approach wherein a bottom-up technique is used to create one-dimensional device structures. We use the vapor-liquid-solid growth method, in which a catalytically active gold nanoparticle forms a eutectic alloy with the nanowire constituents. Our method of growth allows atomically abrupt interfaces between different III-V semiconductors, also for highly mismatched combinations for which conventional growth techniques can not be used. Special emphasis is put on the processing of ohmic contacts to nanowires. We describe the transport properties of nanowires containing heterostructures from which band off-sets between two different binary materials are determined. Finally, we report the creation of double-barrier resonant tunneling diodes in which a single InAs quantum dot surrounded by InP tunnel barriers acts as the active element in the device, resulting in energetically sharp resonant tunneling peaks reflecting tunneling into zero-dimensional states of the quantum dot.