Metals have many disadvantages as components of optical metamaterials. Semiconductor-based materials overcome these problems. We build a high performance, all-semiconductor-based metamaterial by replacing metal with heavily-doped zinc oxide and demonstrate negative refraction in this near-infrared metamaterial. This demonstration could lead to real-world metamaterial devices and unravel many new physical phenomena.  

A range of amorphous structures for a single chemical-composition material (Indium Oxide) were observed; the structure dependent on the growth conditions. The carrier mobility and film (not carrier) density of the films was dependent on growth temperature. Films grown at 0°C and below are amorphous The film density decreased from 7.0 g/cm3 at 0°C to 5.4 g/cm3 at -100°C; the carrier mobility decrease from ~57 cm2/V•s to ~20 cm2/V•s over this same temperature range. The peak in mobility at 0°C adds to the body

Researchers in the Soft Materials Research Center of the University of Colorado Boulder have employed dynamic covalent chemistry to make cross-links that can be controlled optically, enabling materials that can be softened or changed in shape by light.

Mucus clearance is the primary defense mechanism that protects airways from inhaled infectious and toxic agents. In the current Gel-on-Liquid mucus clearance model mucus gel is propelled on top of a “watery” periciliary layer surrounding the cilia. However, this model fails to explain the formation of distinct mucus layer in health or why mucus clearance fails in disease. We propose a Gel-on-Brush model in which the periciliary layer is occupied by membrane spanning mucins and mucopolysaccharides densely tethered to the airway surface.

Two-dimensional (2D) layered materials have many features suitable for optoelectronic devices, but poor quality substrates can degrade optical properties. By encapsulating a monolayer semiconductor in layers of atomically-thin hexagonal boron nitride, a nearly pristine environment can be achieved free from surface roughness and defects of typical substrates.

Princeton researchers alter a sequence of random copolymers and provide the first experimental observations of thermoreversible crew-cut micelles, and thermotropic micro- and macrophase separation in a nonaqueous polymer solution.

Recent advances in gold nanoparticle synthesis combined with functionalization with DNA linkers has enabled the self-assembly of stacks of gold nanodisks in which the optical spectra can be tuned and modulated by controlling the stack structure (e.g., particle spacing, arrangement, and stack length). The figure shows three possible arrangements of the particles, and the corresponding spectra that are associated with the plasmon resonance excitation in the stack.

  MRSEC outreach activities coordinate with Utah Core Curriculum Standards. These sixth-graders are studying the properties of light in their classroom. The Adelante program seeks to increase the expectation of university attendance and success among Hispanic students at Jackson Elementary. Participants: