Study of Ion Migration in Perovskite Solar Cells via X-ray Photoemission Spectroscopy Imaging and Photoluminescence Microscopy

Organic-inorganic hybrid perovskite solar cells (PSCs) attract enormous attention in the field of emerging photovoltaics due to their unique optoelectronic properties and unprecedented advances in performance.

In just over a decade, the power conversion efficiency of PSCs has increased from 3.9% to 25.5%, suggesting this technology might be ready for large-scale exploitation in industrial applications. However, stability and scalability are some of the major concerns that impede the commercialisation of PSCs.

Among these, exploring strategies to enhance the long-term stability of PSCs is a main research topic in the perovskite community.

While it is generally considered that ionic defect states in the perovskite layer such as vacancies, interstitial sites, anti-site substitutions as well as surface and grain boundary defects inevitably lead to the degradation of PSCs, much remains unknown about the fundamental nature of ionic defects and in particular their migration in perovskite materials.

This project will focus on the study of ion migration by a unique combination of electrical and spectroscopic methods which will allow tracking changes in both the compositional and optoelectronic properties of perovskites with the same spatial resolution and thus directly linking the migration of ionic species to their effect on material properties.

By applying this novel methodology, I will explore the effects of perovskite composition, film microstructure and mitigation strategies on the ion migration and investigate how ion migration impacts the stability of perovskite materials.

This project will significantly expand our current understanding of ion migration in PSCs and provide valuable insights for enhancing device stability.