Scientists at Pusan National University in South Korea have leveraged the technique of interfacial passivation to address lead leakage and perovskite degradation due to moisture in Perovskite solar cells.

Perovskite solar cells are considered the strongest contender to replace silicon solar cells. While they achieve high power conversion energy, they also suffer from lead leakage and perovskite degradation due to moisture.

In a study published in the Journal of Energy Chemistry, the researchers said they tested many crown ethers to improve the stability of Perovskite solar cells.

According to Ji-Youn Seo, Assistant Professor and lead researcher: 'This study emphasises the efficacy of interface passivation by achieving increased power conversion efficiency, and demonstrates that crown ether not only blocks lead leakage through the formation of host-guest complexes with lead ions but also imparts strong resistance to moisture to the treated films, showing improved long-term stability in high humidity environments compared to existing solutions. This research highlights the potential of crown ether to simultaneously address lead leakage and long-term stability for sustainable perovskite solar cells ready to advance commercialisation and renewable energy applications.'

The team found that B18C6 was the best ether for interfacial passivation. With B18C6, there was an increased charge carrier lifetime.

The work function (or the minimum energy required to move an electron from a metal’s surface) between the hole transfer material and the perovskite was also improved.

Thus, the researchers obtained an exceptional power conversion efficiency of 21.7 per cent with B18C6. C

This technology can enhance photoelectric conversion efficiency to over 30 per cent when used alongside existing silicon solar cells, thereby increasing the possibility of replacing fossil fuel-based energy sources and contributing to the achievement of carbon neutrality.

'In ten years, this technology could be applied to the energy, display, and semiconductor materials industries through the heterojunction structure,' Dr Seo said.