SUBJECT: Ph.D. Proposal Presentation
BY: Peiyan Yang
TIME: Thursday, October 18, 2018, 12:30 p.m.
PLACE: Love Building, 210
TITLE: Thermal Radiative Properties of Disordered Media as well as Graphene-Coupled Periodic Nanostructures
COMMITTEE: Dr. Zhuomin Zhang, Chair (ME)
Dr. Peter Loutzenhiser (ME)
Dr. Peter Hesketh (ME)
Dr. Michael Filler (ChBE)
Dr. Jud Ready (MSE)


Thermal radiative properties of materials can be tuned by the surface roughness, inhomogeneity or some periodic plasmonic structures. The purpose of this proposal is to investigate how the randomness or micro/nano-scale periodicity will affect and be utilized to engineer the radiative properties of the materials.
Radiative properties of selected thin ceramic plates are studied by measuring their reflectance and transmittance. The scattering and absorption coefficients are obtained using an inverse method based on the measurement. The Lorentz oscillator model is applied to fit the reflectance spectra in order to obtain their optical constants.
A diffusive solar reflector with record-high reflectance is proposed and demonstrated, consisting of a polymer sheet on top of a silver film. The underlying mechanism is explained from a Monte Carlo ray-tracing method and a modified two-flux model. In addition, the measurements suggest a high emittance in the mid-infrared region, promising for passive daytime radiative cooling.
Magnetic polaritons are experimentally demonstrated in several microfabricated grating samples by measuring the specular reflectance, compared with the calculation from the rigorous coupled wave analysis and an LC-circuit model. The gratings could be coupled with graphene for enhanced absorptions and the study of graphene ribbon plasmons.