Low-Loss Optical Metamaterials Based on Mie Resonances in Semiconductor Nanoparticle Composites.

摘要

This document is our final technical report and describes the efforts under contract N00014-11-1-0521. The objective of this work was to establish the feasibility of creating solution processed metamaterials formed from composites of semiconductor quantum dots (QDs). The specific goals of this work included, (1) modeling of the metamaterial's optical properties, (2) developing fabrication techniques and (3) experimental characterization of the materials' optical properties. Modeling was first conducted and it was found that under ideal conditions, a high frequency magnetic response could be created in metamaterials formed from composites of quantum dots utilizing excitonic resonances. However, in experimentally fabricated films using cadmium selenide QDs, it was found that the excitonic resonance is significantly broadened, preventing the high index needed to realize metamaterials with tailored effective permittivity and permeability. To overcome this challenge, lead sulfide QDs were then explored due to their high bulk index. Using lead sulfide QDs it was found that a considerably higher effective constituent index could be achieved. However, it was found that thick QD films and multilayer films could not be realized without inducing severe cracking. Patterning of multilayer films was achieved but due to their thin thickness, optical resonances could not be supported.