Unravelling the photophysics of quantum dot/molecule hybrids

3 minute read

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Triplet-fusion upconversion is a rising strategy that harnesses spin-dependent molecular interactions to transform pairs of long-wavelength (i.e. ‘red’) photons into high-energy (i.e. ‘blue’) light in situ.

Key research advances over the last decade are accelerating the push towards applications. For instance, the ability to convert infrared light to visible wavelengths could enhance the efficiency of solar cells. The ability to selectively transform low-intensity, photochemically inert red light into bond-breaking blue photons could also enhance the volumetric 3D printing schemes that seek to accelerate the mass-customized fabrication of lightweight plastic components.

At the core of any triplet-fusion upconversion system are spin-triplet excitons - molecular excitations that are best generated indirectly via energy transfer from a triplet sensitizer with strong optical absorption.

Particularly, a powerful opportunity exists to create all-in-one hybrid architectures for triplet fusion upconversion by functionalizing the surface of colloidal quantum dots with conjugated molecules, oligomers, and polymers.

The next frontier is to chart, understand, and shape the complex energy and charge flows between the band-edge states of the quantum dot, carrier traps that form via dynamic reconstruction on the nanocrystal surface, and the allowed orbitals of the exciton-accepting molecules that decorate the surface.

In partnership with subject experts working within the Collaboration Centre for Green Energy Materials (CC-GEM) between U of T and the National Research Council of Canada, this will lead to the development of fundamental knowledge to advance the target applications, particularly developing upconverting photo-initiators for volumetric 3D printing.

Project goals

The goals of this project are to:

  1. Design and synthesize a suite of functionalized nanocrystals that can allow for controlled studies of electron, hole, and energy transfer within the hybrid system
  2. Develop critical measurements to track the photophysical dynamics of carrier trapping and charge/energy transfer across their natural, widely ranging timescales to reveal the underlying photophysics, and guide the design of the next generation of self-assembled architectures to achieve electronic passivation of the nanocrystal surface while enabling effective functionalization with purpose-built molecules
  3. Develop improved nanocrystal-sensitized triplet-fusion architectures for use in volumetric 3D printing.

Supervision team

*Click on the researcher's name above to learn more about their publication and grant successes.

Who we are looking for

We are seeking a PhD candidate with the following skills:

  • Demonstrated experience in the field of nanocrystal synthesis
  • Demonstrated ability to gain proficiency in optical spectroscopy techniques and data analysis
  • Demonstrated ability to work independently and as a member of a team.
  • Demonstrated skills in time and project management research organisation, time management and ability to work to priorities.
  • Demonstrated ability to write research reports or other publications to a publishable standard (even if not published to date)
  • Excellent written and oral communication skills.
  • Demonstrated problem-solving abilities.

Further details

The PhD candidate will benefit from the combined expertise of the project supervisors, and the embedding into two research environments.

Professor Trevor Smith at the University of Melbourne will contribute expertise in ultrafast laser spectroscopy. Assistant Professor Mark B Wilson at the University of Toronto will contribute expertise in the synthesis of molecularly functionalized nanocrystals.

This PhD project will be based at the University of Toronto with a minimum 12-month stay at the University of Melbourne.

The candidate will be enrolled in the PhD program at the Department of Chemistry at the University of Toronto, and in the PhD program at the School of Chemistry at the University of Melbourne.

To apply for this joint PhD opportunity, and to view the entry requirements, visit How to apply.

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