PhD Studentship: Topology-enhanced Lanthanide Surfaces for Luminescence Detection

This interdisciplinary project will explore novel designs of plasmonic surfaces based on defined topologies to optimise the plasmonic effect on lanthanide luminescence. Lanthanides have attractive luminescent properties, with a characteristic fingerprint luminescence signal which has long lifetimes and narrow bandwidth. The near infra red emitting lanthanides, Yb, Nd, Er have characteristic profiles which range from 900 nm to 1500 nm. In the project we will use synthetic chemistry to design lanthanide complexes, plasmonic surfaces with biomolecular detection systems targeting analytes. Surface modelling will assist for defined topologies using designed lanthanide emitters. These photonic systems will bring a paradigm shift in integrated photonic systems for optical communications and healthcare.

Research background

Interaction of light with interfaces is very important in optics. Optical devices for detection rely on the strong responses stimulated by light and sensitivity of the detection system. Plasmonic metasurfaces provide an attractive platform to attach active emitters and bio recognition targets in order to modulate light properties upon binding of the target molecule. Plasmonic surfaces can not only enhance the photoluminescience of integrated emitters through the Purcell effect (i.e. increased spontaneous emission due to enhanced optical density of states), but also provide powerful control over the direction and polarization state of the emitted light. Computational designs are employed to optimise surface structural features to enhance the plasmonic effect. Topological Optimisation (or Inverse Design) is a computational design approach for discovering optical structures based on specified functional characteristics. The technique is currently revolutionising the field of nanophotonics by allowing for the algorithmic design of photonic devices such as filters, couplers, splitters and diplexers.

Outcomes

The studies will develop novel plasmonic surfaces with lanthanide luminescent signals enhanced by the structural designs. A modelling methodology for topological design of the surfaces will be developed for both visible and near-infra red emitting lanthanides. The surfaces will modified with biomolecules for detection and their sensitivity will be assessed for the development of optical diagnostic device.

Methodology

Lanthanide emitter complexes will be designed based on previous expertise, using surface active groups to covalently attach the lanthanide complexes on surfaces. ed using nano and photolithography techniques.

Photophysical studies on surfaces will be evaluated using time-resolved and luminescence spectroscopy based on a state of the art spectroscopy setup coupled to microscope for imaging. There is opportunity for computational modelling based on commercial full-wave electromagnetic software like Ansys Lumerical and Comsol Multiphysics.

The teams have collaborated in a DSTL funded project of near IR emitting complexes on gold surfaces. A manuscript is in preparation.

This project will benefit from close synergy with the EU funded H2020 Rise “Non-Conventional Wave Propagation for Future Sensing & Actuating Technologies” project and the EPSRC UK Metamaterials network led by the University of Exeter – the proposed PhD project falls within the remit of both of them.

The project is ideal for a student who holds an undergraduate degree in Chemistry with strong background and interest in Physical chemistry (experimental or computational). The student should have strong interdisciplinary interests and communication skills to liaise within the chemistry and physics groups.

Funding Details

The studentship is open to both home and EU students with settled status in the UK and will cover both the cost of tuition fee and a yearly stipend (at UKRI rate) over the course of the PhD programme.