Optical Modeling And Analysis Of Disordered Plasmonic Nanoparticle Ensembles
Nanoscience and Nanotechnology
Plasmonic nanoparticle synthesis provids a facile and cost-effective bottom-up solution to fabrication of nanoscaled structures. With effective packaging methods like embedding into polymer composites and superlattice assemblies, the chemically synthesized nanoparticles are promising candidates for functional devices. However, compared with precisely patterned surfaces commonly used for device fabrication, the structural inhomogenity and disorder in nanoparticle ensembles give rise to challenge in their characterization using conventional methods and in turn, their application. This work aims to develop models as guideline to design facile characterization methods that can be used to effectively describe the properties of disordered plasmonic nanoparticle ensembles. Two types of nanoparticle ensembles will be examined, including nanoparticle polymer composites and nanoparticle assemblies, representative of disordered nanoparticle packing on two length scales. Multipole expansion of different types and the effective medium approximation will be extensively used to establish models describing the effective optical properties of these systems as an ensemble average. Various analytical and numerical electrodynamic calculations will be performed to analyze the dependence of the effective optical response on structural parameters of the ensembles. The models can be used as a future guideline to design both synthetic procedures and characterization methods for chemically syntheized nanoparticle ensembles according to specific desired applications.