Molecular Origins of Stability in Organic Photovoltaic Materials

About the Project

A 3.5-year PhD position is available in the field of experimental nanoscience at surfaces and molecular-scale imaging of conjugated polymers in the group of Prof. Giovanni Costantini at the University of Birmingham.

About the research: Organic photovoltaics (OPVs) are emerging as a lightweight, flexible, and potentially sustainable alternative to conventional silicon-based solar cells, with applications ranging from building-integrated photovoltaics and solar greenhouses to aerospace technologies. Despite major advances in efficiency, the long-term operational stability of OPVs remains a key bottleneck, largely due to the intrinsic instability of their active materials.

A promising strategy to address this challenge involves conjugated block copolymers, in which electron-donor and electron-acceptor units are combined along the same polymer backbone. While these materials offer exciting opportunities for enhanced morphological control and stability, a detailed understanding of the molecular-scale arrangement and interactions between donor and acceptor segments is still lacking. Gaining such insight is essential for establishing rational design principles for the next generation of efficient and stable OPVs.

About the project: The Costantini Lab has recently demonstrated that the combination of electrospray deposition (ESD) with scanning tunnelling microscopy (STM) enables the deposition of intact conjugated polymers in ultrahigh vacuum (UHV) and their imaging with unprecedented sub-molecular resolution. This breakthrough has opened a transformative new route for the characterisation of conjugated polymers, leading to the first molecular-scale visualisation of these functional macromolecules. In this PhD project, the ESD-STM methodology will be applied to investigate the nanoscale morphology, molecular organisation, and local electronic properties of donor–acceptor conjugated block copolymers relevant to organic photovoltaics, including PM6, Y6, and their covalently linked variants. By directly imaging their microstructure with sub-molecular precision, the project aims to establish structure–function relationships and uncover the mechanisms governing stability and charge transport. The insights gained will feed back into materials design through close collaboration with world leading synthetic groups, linking molecular architecture directly to device-relevant properties.

What we offer:

The successful candidate will have access to unique, world-leading ESD-STM instrumentation and will be trained in the operation of sophisticated experimental setups at the forefront of surface science and molecular imaging. The student will work closely with senior researchers and international experts, within a highly collaborative and interdisciplinary research environment. While the project is firmly rooted in experimental nanoscience at surfaces, it directly contributes to the development of greener, more functional photovoltaic materials. The work will involve close collaboration with leading synthetic groups at the University of Cambridge, University of Oxford, Imperial College London, Hasselt University, and Princeton University.

Who we are looking for: We welcome applications from motivated students with backgrounds in physics, chemistry, materials science, or engineering. The ideal candidate will have a strong interest in hands-on experimental research and be keen to operate sophisticated instrumentation involving mechanical, electronic, and vacuum systems. Intellectual curiosity and a genuine interest in understanding fundamental physical and chemical mechanisms are essential. Prior experience in scanning probe microscopy and/or surface science is advantageous but not required.

References:

D.A. Warr, et al., Sci. Adv. 4, eaas9543 (2018); M. Xiao, et al., Adv. Mater. 32, 2000063 (2020); R.K. Hallani, et al., J. Am. Chem. Soc. 143, 11007 (2021); S. Moro et al., ACS Nano 16, 21303 (2022); J. Vanderspikken, et al., Adv. Funct. Mater. 2309403 (2023); J.F. Coker et al., PNAS 121, e2403879121 (2024); X. Wu et al., Nat. Commun. 16, 7031 (2025).

Funding Notes

Funding for this position is open to UK applicants.