Postgraduate research opportunities Photonic Supraparticles – a novel material platform for Nanolasers, Sensing, and Solid-state Lighting

Progress in Photonics (and technology in general) relies heavily on advanced nanomaterials. Luminescent quantum dots for example are enabling lasers, innovative lighting and display technologies, enhanced photovoltaics, novel bioimaging labels, and again novel types of classical and quantum optical sources, in turn unlocking and/or enhancing applications in wide ranging fields and contributing to address grand challenges. Yet, the impact of nanomaterials can still be significantly enhanced by creating mesoscopic structures, so-called supraparticles or supracrystals a few tens to a few thousands of nanometres in size. These are closed-packed assemblies of quantum dots (and other nanocrystals or molecules) – the latter acting as the building blocks or ‘nano-bricks’ for the suprastructures (SPs).

Our team has established a range of emulsion-templated self-assembly processes to fabricate spherical semiconductor supracrystals from the bottom-up; we have shown we can make microlasers this way. We are also exploring hybrid top-down fabrication methods. Now, we are stepping up our efforts to create multifunctional supraparticles by blending different types of nanobricks including upconverting nanoparticles, tailoring the design and geometry of the SPs, coupling to plasmonics, and by engineering the surface chemistry of SPs. We have for example recently obtained SP microlasers functionalised with biomolecular probes, coupled a SP to an optical waveguide, as well as demonstrating SPs emitting at different wavelengths.

This PhD project will explore a particular aspect of this exciting SP technology, which depending on the candidate and associate funding could have a focus on:

1. Nanolasers/Spasers: SPs are an ideal platform to explore structures fabricated from the bottom-up that couple laser cavity modes with plasmonic resonances. We want to devise and study such structures in order to demonstrate plasmonic nanolasers (or spasers) that breaks the diffraction limit of light.
2. Sensing: the integration of surface functionalised SPs with fluidics, waveguides/fibres, and laser or LED excitation sources, in order to demonstrate a (bio)sensing instrumentation.
3. Laser/LED lighting and Optical communications: Luminescent SPs can act simultaneously as wavelength shifters (downconverter or upconverter depending on what it is made of) and as optical antennas (dielectric resonators). There is therefore the opportunity to enhance the process of light conversion while simultaneously accelerating the time response through cavity (antenna) effects. The acceleration of the emission can also be obtained by the addition of plasmonic elements. Fast SP converters could then be applied to optical sources and detectors for applications in optical communications in the UV, visible (VLC), and even the mid-infra-red. The project could look into the design and characteristics of single SPs and SP ensembles for these applications, as well as develop techniques for the integration of SPs with optical sources and photodetectors (for example via printing).

Photocatalysis: We are interested in developing photonic SPs with photocatalytic properties – which can be obtained by combining luminescent nanobricks with photocatalytic nanoparticles (for example Titania). These have huge potential for health applications (for example as combined imaging and photodynamic therapy agents), environmental and defence applications, as well as for energy generation.

Further information

Institute of Photonics: The Institute of Photonics (IoP), part of the Department of Physics, is a centre of excellence in applications-oriented research at the University of Strathclyde.  The Institute’s key objective is to bridge the gap between academic research and industrial applications and development in the area of photonics. The IoP is located in the £100M Technology and Innovation Centre on Strathclyde’s Glasgow city centre campus, at the heart of Glasgow’s Innovation District, where it is co-located with the UK’s first Fraunhofer Research Centre. Researchers at the IoP are active in a broad range of photonics fields under the areas of Photonic Devices, Advanced Lasers and Neurophotonics.

Strathclyde Physics is a member of SUPA, the Scottish Universities Physics Alliance.

The University of Strathclyde has, in recent years, been the recipient of the following awards: The Queen’s Anniversary Prizes 2019 & 2021 for Higher and Further Education; University of the Year 2012 & 2019, Times Higher Education; University of the Year 2024 Runner-up, Daily Mail University of the Year Awards; Scottish University of the Year 2024, Daily Mail University of the Year Awards.