Mesoscale simulations of organic solar cells

Organic photovoltaics (OPVs) show much promise for next-generation solar cells thanks to their low cost, and the fact that they are flexible and can be printed over large areas. Researchers have succeeded in 2018 in improving the power conversion efficiencies of these cells to 15%, allowing them to compete with perovskite which have also excited much interest. These cells are more stable and less toxic than the perovskite solar cells. This studentship will adapt and run mesoscale models of polymer and small molecule packing developed in ABW’s group to understand how molecular packing influences charge and energy motion by a kinetic Monte Carlo simulation that predicts cell efficiencies [1]. We can then establish the best materials for these devices.

Conventional methods demand too much CPU time to generate morphologies on this scale, limiting previous exciton diffusion studies to on-lattice models, limiting applicability. A new method has been developed by ABW’s group which can generate morphologies on length scales of 10-100 nm in significantly reduced CPU times compared to the widely used molecular dynamics approach [2]. It will be used to generate the amorphous structures of polymer nanoparticles. The charge and energy dynamics can be simulated and compared to new experimental work carried out in Australia on solar modules comprised of these nanoparticles [3]. For these materials, eco-friendly fabrication is achievable with colloidal ink whose preparation enables the deposition of photoactive layers from water.

The project will involve running existing codes and improving them to investigate OPV materials and structures studied by the experimental groups of Da Como (Bath) and Greenham, Friend and Sirringhaus (Cambridge) and CSIRO Energy Technology and Centre of Organic Electronics, University of Newcastle, Australia. This project is also relevant to organic charge transport layers in perovskite solar cells, to organic light emitting diodes used in display devices and to organic field effect transistors that are used for plastic electronics applications such as sensors. ABW is funded by several EU and EPSRC projects that are linked to industrial and academic groups across the EU working on organic semiconductors and perovskite cells.

Applicants should hold, or expect to receive, a First Class or good Upper Second Class Honours degree in Physics or Chemistry, or the equivalent from an overseas university. An interest in writing and adapting computer codes is essential. A master’s level qualification would also be advantageous.

Informal enquiries are welcomed and should be directed to Professor Alison Walker, [Email Address Removed].

Formal applications should be made via the University of Bath’s online application form for a PhD in Physics:
https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUPH-FP01&code2=0013

More information about applying for a PhD at Bath may be found here:
http://www.bath.ac.uk/guides/how-to-apply-for-doctoral-study/

Anticipated start date: 30 September 2019.