New Perovskite Solar Cells Research Outlines a Durable Alternative to Silicon

Oxford researchers, including Trinity DPhil Philippe Holzhey, have demonstrated a new way to create stable perovskite solar cells.

The solar cells have fewer structural and energetic defects and can potentially match commercial silicon’s durability, making them promising next-generation solar cells. 

By removing the solvent dimethyl-sulfoxide and introducing dimethylammonium chloride as a crystallisation agent, the researchers were able to better control the intermediate phases of the perovskite crystallisation process, leading to thin films of greater quality, with reduced defects and enhanced stability. Large groups of up to 138 sample devices were then subjected to rigorous accelerated ageing at high temperatures and in real-world conditions.

The new perovskite solar cells created by the team were shown to outperform the control group, demonstrating resistance to thermal, humidity, and light degradation. This is a vital step forward to matching commercial silicon’s stability and makes perovskite-silicon tandem devices a much more realistic candidate for becoming the dominant next-generation solar cell.

Led by Professor Henry Snaith (Oxford University) and Professor Udo Bach (Monash University), the work has been published in the journal Nature Materials.

DPhil student Philippe Holzhey is a Marie Curie Early Stage Researcher from Oxford’s Department of Physics and joint first author on the work, said: 'It's really important that people start shifting to realise there is no value in performance if it's not a stable performance. If the device lasts for a day or a week, there's not so much value in it. It has to last for years.

'New photovoltaic materials like perovskites that can significantly improve existing PV technologies are urgently needed, given our need to adopt renewable energies to tackle climate change. I hope our work sheds some light on some of the difficulties perovskite solar cells face and helps overcome them. We had a fantastic team of people with very different scientific backgrounds, from pharmaceutical science, engineering disciplines, chemistry and physics, which was the key to success for these projects. Without each and every one of them, we wouldn’t have made it.'

The researchers hope their work will encourage a greater focus on the intermediate phase of perovskite crystallisation as an essential factor in achieving greater stability and commercial viability. 

In addition to the Nature Materials publication, Philippe has published additional articles on his work with perovskite solar cells in Joule, and a paper in Advanced Energy Materials on a new method of measuring ideality factor maps for solar cells using photoluminescence.