Materials World Network: Nano-structured materials from nanoparticle- and block copolymer assemblies for nanophotonics and optoelectronics

Lead Research Organisation: Imperial College London
Department Name: Dept of Physics

Abstract

Here we propose to investigate the synthesis and characterization of novel classes of metal-based nano-structuredparticles and composites with well-defined geometry and connectivity. The materials are obtained by a modular bottom-upapproach of metal-containing nanoparticles (NPs) with core-shell architecture as well as nanocomposites from metal NPsand block copolymers (BCs) as structure-directed agents. The aim of the proposed program is to understand theunderlying fundamental chemical, thermodynamic and kinetic formation principles enabling general and relativelyinexpensive wet-chemistry methodologies for the efficient creation of multiscale functional metal materials with noveloptical property profiles that may revolutionize the field of nanophotonics/plasmonics/ metamaterials, enabled by nmscalecontrol over the underlying structure over large dimensions. The proposed research includes synthesis of allnecessary organic/polymer and inorganic components, characterization of assembly structures using various scattering,optical and electron microscopy techniques, as well as thorough investigations of their optical properties includingsimulation and modeling efforts, and work towards major novel optics in the form of sub-wavelength imaging, highlysensitive hot-spot arrays over macroscopic dimensions for sensing, and sub-wavelength waveguiding. While the mainfocus of our proposed work lies on non-magnetic materials and the assessment of linear optical properties of thefabricated compounds, a crucial point is that we are aiming at synthesis approaches that can be generalized over a widerclass of materials systems. A final thrust of the program addresses a particularly topical exploitation area, where we willintegrate specific plasmonic structures into hybrid solar cells and characterize and optimize plasmon enhancedphotogeneration of charges and subsequent solar cell efficiency. If successful this will lead to a new generation, or classof photovolatics, namely plasmonic solar cells.

Planned Impact

The project is focussed on creating new metallic nanomaterials with novel optical properties; developing the routes to realize the targeted structures, and fully characterising the ensuing interaction with light. The application targeted in the final Thrust is hybrid photovoltaics, a device which could majorly benefit from improved control of the optical fields. With regards to the photovoltaics application area, breakthroughs in technological advancement are most effectively achieved through open-collaborative environments, such as that proposed here. It is anticipated that the knowledge attained during this project will greatly enhance our understanding of the critical processes occurring in hybrid photovoltaic systems, and specifically a new generation of photovoltaics, namely plasmonic solar cells . The interdisciplinary nature of the research, which borders on to Materials Science, Physics, Chemistry, and engineering, will have a high impact on the broader scientific community and an ever increasing number of university groups and start-up companies researching into plasmonics, photonics organic and hybrid electronics and electrochemical systems. The plasmonic photovoltaic systems are being developed with the intention to make real advances in terms of absolute performance to the state-of-the-art technology. The technological advancements are likely to lead towards commercial exploitation, with eventual contribution to global energy production. There are a number of companies, with whom the team has contact, who are specifically developing hybrid dye-sensitized solar cells (BASF, Merck, Bosh to name a few). Routes developed in this project to improve the efficiency could directly impact the time to commercialisation of these concepts. In this context, steps leading to significant advancements will be patent protected and exploited through the most suitable means, bringing wealth to the Universities, the UK, Europe and the USA as a whole. Nanophotonics is a new, rapidly developing field, with almost certainly many unforeseen applications. The impact of this work is likely to be far greater than solely the photovoltaic industry. Applications to mine include light emitting diodes and laser diodes, but no doubt advances in quantum information and optical processing of memory will significantly benefit from our endeavours. This project offers an ideal training ground for PhD students from all aspects of physics, chemistry and material science, with key training in the multidisciplinary field of nanotechnology and nanophotonics. We are part of the PVNet consortium in the UK and the Supergen excitonic solar cell consortium, actively collaborating with many of the leading scientists in the field. The directly participating students and also all other students within these groups will hugely benefit from exposure to other leading groups within the UK and globally. Lastly, both Imperial College and the University of Oxford will greatly benefit from being part of this trans-national collaboration, contributing towards maintaining and improving their reputation as a world leading research institution in the USA.
 
Description * Diblock copolymer self-assembly methods can lead to three-dimensional crystals that show negative refraction of light, and also optical chirality; the method could enable scalable fabrication of novel optical materials

* Interference effects in metallic nanostructure assembles can be described by a general theory based on Fano resonances

* Identification of viable graphene/silicon sandwich structures for transfer of optically encoded information

* Demonstration of sicilon carbide metamateri
Exploitation Route Development of hybrid sensing platforms
Sectors Digital/Communication/Information Technologies (including Software),Security and Diplomacy