Interfacial Engineering of Perovskite Solar Cells by Computational Modelling and Device Testing

The central aim of this project is to use atomic scale computational modelling to describe structures and processes at the interfaces of perovskite solar cells (PSCs). Recent research has uncovered molecules and other interfacial layers suitable for improving the efficiency and stability of PSCs, but challenges remain in understanding how they work to achieve these goals.

Targeted development of improved interfacial engineering strategies is hence obstructed. Accordingly, this project seeks to elucidate the working mechanisms for stability improvement and efficiency gains at the interfaces in PSCs and aid the development of more effective strategies for interfacial engineering towards these goals.

Perovskites are soft materials sensitive to degradation, and the interfacial layers used to stabilise them and passivate their defects exist on the nanoscale. These two factors make detailed characterisation of PSCs challenging and time-consuming. Atomistic modelling techniques, including density functional theory (DFT) and molecular dynamics (MD), provide a means to investigate these materials at the shortest length-scales without these experimental barriers.

Further, recent developments in these techniques using machine-learned inter-atomic force-fields have enabled probing at an even greater range of length and timescales. Use of these techniques in this project will uncover how a wide range of possible novel molecules and nano-layers in PSCs interact to inhibit degradation processes and passivate defects.

For a complete picture, atomistic modelling and experimental characterisation should be combined. In this project, computational techniques will be used to ameliorate experimental data from x-ray-based characterisation and photoluminescence measurements, which provide broader structural and performance information respectively. Detailed understanding of the mechanisms relevant for degradation and performance in PSCs will enable and inform comprehensive testing and iterative improvement of novel interfacial engineering strategies.

This project can thus ultimately lead to highly efficient and stable solar cells based on perovskite materials, backed by a complete understanding of how they may be achieved.