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School of Physical and Chemical Sciences

Minimizing exciton and charge losses in next generation organic solar cell materials with extremely weak vibronic coupling, a single molecule approach

Research Group: Chemistry
Number of Students: 1
Length of Study in Years: 4 Years
Full-time Project: yes

Funding

Funding is provided via the China Scholarship Council.  

  • Available to Chinese applicants only.
  • Applicant required to start in September 2025.
  • The studentship arrangement will cover overseas tuition fees for the duration of the studentship.

 

Project Description

Organic solar cells, while highly efficient, continue to exhibit voltage losses larger than those of most inorganic solar cells, limiting their power conversion efficiency. One of the primary causes is non-radiative charge and excited state relaxation processes. This project aims to investigate these mechanisms in individual molecules using single-molecule techniques (drawing on Dr. James Thomas's expertise) and compare the findings to bulk laser spectroscopy experiments (drawing on Dr. Dimitrov's expertise). The results are expected to provide unprecedented insights into modern organic solar cell materials. This will primarily be an experimental project, utilising state-of-the-art equipment at QMUL and materials from Dr. Brandt’s group, as well as systems that have garnered significant recent interest: Nature, 629, p. 355 (2024).

Supervisors:

Stoichko Dimitrov will be the main supervisor (Spectroscopy | Dimitrov Lab); Dr James Thomas (Thomas lab) a co-supervisor; Dr Jochen Brandt a co-supervisor (Brandt Lab).

Dimitrov leads the Photophysics and Photochemistry group with world leading laser spectroscopy and materials development expertise at the Department of Chemistry at QMUL (ranked 8th for Impact and 9th for research outputs in the UK). Dr Thomas leads a group on single molecule characterisation and transistor devices at the Department of Physics at QMUL. Brandt leads a group working on the interaction of chirality and spin at the Department of Chemistry at QMUL.

 

Relevant publications:

Requirements

Application Method:

To apply for this studentship and for entry on to the Chemistry programme (Full Time) please follow the instructions detailed on the following webpage:

https://www.qmul.ac.uk/spcs/phdresearch/application-process/#apply

Deadline for application - 29th of January 2025

Supervisor Contact Details:

E-mail: s.dimitrov@qmul.ac.uk

SPCS Academics: Dr Stoichko Dimitrov

Research Group: Chemistry
Number of Students: 1
Length of Study in Years: 4 Years
Full-time Project: yes

Funding

 

Funding is provided via the China Scholarship Council.  

    • Available to Chinese applicants only.
    • Applicant required to start in September 2025.
    • The studentship arrangement will cover overseas tuition fees for the duration of the studentship.

Project Description

 The introduction of chirality into conjugated organic semiconductors can result in more sustainable electronic devices, such as more efficient OLED screens for smartphones or TVs, and bring new functionality to emerging technologies. An extraordinary recent discovery in chiral materials research has been the observation of the Chiral Induced Spin Selectivity (CISS) effect: spin-selective charge transport through chiral molecules. The spin control exhibited by chiral molecules could lead to the enhanced hydrogen production in water splitting and faster, more efficient devices, by enabling the combination of spin and charge (spintronics) in computer processors. However, the full technological potential of the CISS effect has yet to be realised, partly due to our limited understanding of the effect. I propose to untangle the different contributions to CISS for the first time by measuring how systematic variations of an electron’s chiral and spin environment impact a material’s spin filtering properties.

There are two possible projects and the successful candidate may decide to pursue either one of these or a combination of both. The projects are: 1) a synthetic organic project to develop the first general enantioselective synthesis of compounds called helicenes that possess a helically chiral – yet fully aromatic – backbone. This project will employ transition metal catalysis and provide training in reaction optimisation and methodology development. Project 2) is a highly interdisciplinary project to synthesise helicenes and use them to investigate the CISS effect. The helicenes will be prepared using a photochemical flow synthesis currently being developed by the Brandt group (DOI 10.26434/chemrxiv-2024-cgnhq ). While traditional, batch-based photochemical reactions can be difficult to scale, our preliminary results have shown robust helicene yields up to 9.8 mmol (79% yield). The synthesised materials will then be characterised in solution and the solid-state using advanced characterisation techniques that probe the photophysical and electronic properties (e.g. spin filtering, UV/vis, (magnetic) circular dichroism, cyclic voltammetry). The ideal candidate should have some experience in synthetic chemistry and be interested in exploring a highly interdisciplinary, collaborative, and dynamic field of scientific research.

 

Requirements

Application Method:

To apply for this studentship and for entry on to the Chemistry programme (Full Time) please follow the instructions detailed on the following webpage:

https://www.qmul.ac.uk/spcs/phdresearch/application-process/#apply

Supervisor Contact Details:

For informal enquiries about this position, please contact Dr Jochen Brandt

E-mail: j.brandt@qmul.ac.uk

Application Method:

To apply for this studentship and for entry on to the PhD programme (Full Time) please follow the instructions detailed on the following webpage:

https://www.qmul.ac.uk/postgraduate/research/subjects/chemistry.html

Further Guidance: http://www.qmul.ac.uk/postgraduate/research/

Deadline for applications: 31st of January 2025

SPCS Academics: Dr Jochen Brandt