Novel hybrid organic/inorganic 2D photonic quasicrystals with 8-fold and 12-fold diffraction symmetries

Quasiperiodic crystals (QCs) are a new class of materials that exhibit long-range aperiodic translational order and high rotational symmetries. Unlike periodically arranged photonic crystals (or photonic band-gaps), PQCs possess unique light localization and transport properties related to their complex, multi-fractal energy spectra. Advances in 2D photonic structures are expected in the introduction of non linear and/or active functionality into a 2D PQC. One-dimensional semiconductor nanostructures are likewise promising materials both in fundamental research and in practical applications. CdSe/CdS rods present the appealing characteristics of strong and tunable light emission from green to red, are highly fluorescent and show linearly polarized emission. These characteristics open the way to a new class of hybrid devices based on polymers and colloidal NRs in which the unique optical properties of the inorganic moiety are combined with the processability of the host matrix to develop new high performing optical devices such as organic light-emitting diodes, ultra-low threshold lasers and non-linear devices. One of the challenges of these applications is the incorporation of inorganic nanoparticles into organic polymer matrices, since this is usually accompanied by phase separation, aggregation of nanoparticles, loss of transparency and luminescence quenching due to exciton energy transfer. In this paper two-dimensional (2D) hybrid PQCs which consist of air rods in a nanocomposite prepared by incorporating CdSe/CdS core/shell nanorods (NR) in a polymer are proposed and experimentally demonstrated. Scanning electron microscopy and far field diffraction are used to characterize the experimental structures.