Development and Applications of Nanowire Nanophotonics

Abstract : The controlled and predictable synthesis of nanowires and nanowire heterostructures that serve as the basic nanoscale building blocks for photonic devices has been carried out. Nanocluster catalyzed growth was used to prepare gallium nitride based nanowire materials, including radial nanowire heterostructures in which the composition and/or doping was modulated perpendicular to the axis of a nanowire. Scanning electron microscopy and transmission electron microscopy were used to characterize the detailed structure and composition of nanowires down to the atomic level, and demonstrate that desired nanowire structure could be made in a controlled manner. In addition, the critical optical and optoelectronic properties of the nanowire and nanowire heterostructure building blocks, and their behavior as photonic device elements, including nanoscale light-emitting diodes, lasers and avalanche photodiodes were characterized. Photoluminescence studies showed that at the single nanowire level that nanowires exhibit emission colors that were tuned specifically by the composition of the nanowires. Nanolithography was also used to make electrical contacts to nanowire structures and use combined optical microscopy and electrical transport measurements to demonstrate the successful demonstration of the first multi-color nanoscale light-emitting diodes, the first nanowire electrical injection laser, and the first nanowire avalanche photodiode detector.