Qi Jiang: Solar star

A standout scientist in the global race to boost the performance of solar cells, Qi Jiang is keen to see perovskite solar cells — the fastest-improving solar technology to date — meet their potential.

Compared with the silicon cells that dominate the US$160-billion-a-year global solar energy industry, solar cells using perovskite semiconductors are cheaper to manufacture and offer similar light-to-energy conversion efficiency. But they are prone to decay and instability in the harsh conditions that solar cells endure, and the conversion-efficiency rates achieved on small surface areas in laboratories have proved difficult to replicate at scale.

Another challenge, says Jiang, is that the highest efficiency perovskite cells include lead, an environmental hazard. “We need to think of ways to prevent leakage and effectively recycle these solar cells.”

In 2019, Jiang and her colleagues demonstrated how improvements in power conversion and durability can be gained by the use of a phenethylammonium iodide film on the surface of the perovskite layer within the cell. The paper, with Jiang as lead author, was the most highly cited among articles in the Nature Index with Chinese-affiliated authors that year (Q. Jiang et al. Nature Photon. 13, 460–466; 2019).

Research into perovskite solar cells is drawing widespread attention, particularly in China, which accounts for approximately 80% of the global share of solar-cell manufacturing. In 2019, six of the ten most highly cited articles with significant contributions by Chinese-affiliated authors in the Nature Index were related to solar energy technologies. Four of these papers were focused on perovskite solar cells. “They are very promising and extremely simple to process in the lab, so many researchers all over the world are getting into this area,” says Jiang.

Jiang developed an interest in semiconductors while studying microelectronics at Hubei University in Wuhan, the capital city of central China’s Hubei province. She began investigating their potential in solar cells as a PhD and postgraduate researcher at the Chinese Academy of Sciences Institute of Semiconductors in Beijing, and co-authored the highly cited Nature Photonics article with colleagues from there and the University of Chinese Academy of Sciences.

In 2018, Jiang moved to the United States, where she continued her research into perovskite cells at the National Renewable Energy Laboratory in Golden, Colorado. It was a valuable opportunity to experience a different research culture, she says. “It allowed me to build my achievements and exercise my independence on research.”

Jiang says the global shortage of conventional semiconductors, attributed to pandemic-induced supply-chain disruptions, highlights the importance of developing alternatives for use in energy harvesting. “The raw materials for making perovskite solar cells are very cheap and easy to get,” she says.