Metal-organic framework composites for optoelectronics

Summary

Changing the way we use energy is pivotal in reducing emissions, and structural studies of emerging materials underpins next-generation technologies. Metal–organic frameworks (MOFs), more frequently associated with crystalline and porous structure with applications in chemical separations, have recently taken off in glassy and amorphous forms. Notably, they offer exceptional protective coatings for semiconductors used in solar energy and lighting applications for much needed extensions to device lifetimes. This project will develop and apply advanced electron microscopy approaches to probe these crystalline and amorphous composite structures and to understand their optical properties (e.g. absorption and luminescence).

Scanning transmission electron microscopy offers unique insights into the nanometre to atomic scale structure of materials. However, MOFs are often very fragile when exposed to high energy electron beams, posing a significant challenge for electron microscopy of MOFs. At Leeds, we have been developing a suite of techniques for low-dose electron diffraction, spectroscopy, and imaging for MOFs and other beam-sensitive materials [1-3]. This project will build on these tools to gain insight into the fundamental principles MOF glasses and halide perovskite-MOF composites.

The project will have a primary focus on structural and chemical characterisation, along with some opportunities to carry out MOF synthesis. The PhD researcher will receive training to drive forward their research using approaches including electron diffraction, pair distribution function analysis, and vibrational, optical, and core ionisation spectroscopy. The project will draw on materials science, chemistry, physics, and engineering principles. Applications are welcome from undergraduate degrees in any related field.

We are keen to support and develop an inclusive community of researchers, with the aim for equity for marginalised researchers. If you are interested, please email Sean Collins (s.m.collins@leeds.ac.uk) for informal inquiries.

[1] A. F. Sapnik et al. Commun. Chem. 2023, 6, 92.
[2] J. Hou et al. Science 2021, 374, 621-625.
[3] S. M. Collins et al. Nano Lett. 2021, 20, 1272-1279.

Additional information

The advanced electron microscopy techniques used in the project will involve the use of equipment at the University of Leeds and the Leeds Electron Microscopy and Spectroscopy (LEMAS) Centre at the Bragg Centre for Materials Research. Instrumentation at LEMAS includes a new Tescan Tensor dedicated scanning transmission electron microscope, one of the first two installed in the world, as well as cryogenic plunge-freezing and cryo-transfer, focused ion beam facilities, and capabilities for electron beam spectroscopy, diffraction, and tomography (three-dimensional imaging).

The PhD researcher working on this project will join an enthusiastic and creative team of researchers working across a range of topics from electron microscopy of organic semiconductors and small molecule organic crystals to MOF synthesis. The research group is joint between the School of Chemical and Process Engineering and the School of Chemistry at the University of Leeds.

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.