Engineering Wave Transport with Disordered Materials

Lead Research Organisation: University of Surrey
Department Name: ATI Physics

Abstract

The aims of this project are to take a radical look at engineering the wave transport and generation by employing designer disordered materials. The main goals are related to identifying the effects of structural correlation on photonic/elastic and mechanical excitations and explore new applications including energy conversion and solar cells, opto-mechanic devices and novel types of lasers. The project will also investigate the thermalisation of the electromagnetic radiation in semiconductors and explore the possibility of controlling their thermal response through micro-structuring. The project will balance theoretical and computational activities and will maintain a strong collaboration with experimentalists whenever possible.

Sub-projects:
1) Designer Materials for enhanced radiation absorption analysis of the absorption of radiation by periodic disordered media:
- Identify the effect of the presence/absence of correlation on the absorption of the solar radiation.
- Explore various slab architectures and investigate their performance as solar absorbers.
- Identify the transition point at which the order-disorder transition results in a champion absorber material.
- Explore other structuring, such as quasi-crystalline arrangements.

2) Opto-mechanics:
- Study the controlled coupling of optical and mechanical excitations.
- Identification of optimal architectures that allow for the simultaneous control of optical and mechanical waves.
- Phoxonic band gap materials: periodic versus disordered structures.
- Transport studies.
- Disordered snow-flake structures.
- Waveguide and Cavity Modes for enhanced acoustic-optical coupling.
- Fully nonlinear coupled elastic-acoustic waves.
- Phoxonic (Cascaded) Lasing Structures.
- Raman effect in disordered structures.

3) Mechanics:
- Identify a direct route for the realisation of super-strong, robust, flexible and lightweight materials by exploring the connection between structure and mechanical functionality.
- Employ the framework of local self-uniformity (LSU) to tailor the mechanical properties of the micro-structuring to the needs (including scale and geometric shape) of the required component functionality.
- Study of the mechanical properties of gyroid structured scaffold structures.
- Exploration of amorphous scaffold structures to minimise the dependence of the mechanical strength depends on the high-symmetry direction/planes of mechanical failure.
- Investigation of isotropic structures (disordered and/or quasi-crystalline) for super-strong materials.
- Anderson localisation.

4) Thermalisation of the electromagnetic radiation in semiconductors:
- General description of thermal radiation in micro-structured semiconductor materials.
- Incorporation of the direct atomic/electronic interactions with light by adding electronic transition rate equations into Maxwell's equations and analysis of the thermal equilibrium. Electronic transitions in two- and four- level atoms are coupled and concurrently solved with the electromagnetic fields through an active component of the polarization vector, thus incorporating saturable absorption, stimulated and spontaneous emission, as well as external pumping and draining.
- Derivation of a generalized master equation for the photon-electron and phonon energy transport in micro-structured semiconductor materials.
- Analysis of thermos-photonic effects in micro-structured photonic materials.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509772/1 01/10/2016 30/09/2021
1911140 Studentship EP/N509772/1 03/07/2017 30/09/2020 Richard Cykiert Spalding
 
Description A novel protocol has been implemented to design disordered, nanoscale surface patterning for a solar cell to acheive isotropic broadband solar absorption in the visible wavelength range. Significant absorption efficiencies can be obtained via this protocol; however it is the physical origin of the enhanced absorption that is thoroghly investigated using several analytical methods.
Exploitation Route This work aims to explore the physical origins of wave phenomena observed in disordered materials; from solar absorption to lasing. A detailed understanding of the physics will inform and guide the design of disordered materials towards solutions that are best optimised for their applications. This work can therefore be a usefool tool for any study that could benefit from using disordered media as a means of engineering the flow of waves, for instance accoustics, optics and information technologies.
Sectors Digital/Communication/Information Technologies (including Software),Electronics,Energy