Description: III-V nitrides have been put to use in a variety of applications including laser diodes for modern DVD devices and for solid-state white lighting. Plasmonics has come to the foreground over the past decade as a means for increasing the internal quantum efficiency (IQE) of devices through resonant interaction with surface plasmons which exist at metal/dielectric interfaces. Increases in emission intensity of an order of magnitude have been previously reported using silver thin-films on InGaN/GaN MQWs. the dependence on resonant interaction between the plasmons and the light emitter limits the applications of plasmonics for light emission. This dissertation presents a new non-resonant mechanism based on electrostatic interaction of carriers with induced image charges in a nearby metallic nanoparticle. Enhancement similar in strength to that of plasmonics is observed, without the restrictions imposed upon resonant interactions. in this work we demonstrate several key features of this new interaction, including intensity-dependent saturation, increase in the radiative recombination lifetime, and strongly inhomogeneous light emission. We also present a model for the interaction based on the aforementioned image charge interactions. Also discussed are results of work done in the course of this research resulting in the development of a novel technique for strain measurement ...

Description: This article discusses formation and characterization of ion beam assisted nanosystems in silicon. Abstract: Even though silicon is optically inactive, the nanoscale particle structures (e.g. SiC) in Si or silica matrices are potential candidates for light emitting solid state device applications with higher operation temperatures. The synthesis of these nanostructures involves ion implantation and subsequent thermal annealing. The film thickness and sizes of the nanostructures can be controlled by ion energy, fluence, and annealing conditions. Particle accelerator based characterization was used at different stages of formation and analysis of these nanosystems in Si. Results will be presented using infrared spectroscopy (IR), X-ray diffraction spectroscopy (XRD), and photoluminescence (PL) spectroscopy.