UNSW researchers set a new efficiency record for a kesterite (CZTS) solar cell, achieving 13.2%
Published in Nature Energy, the research outlines a defect-reduction process called passivation using hydrogen annealing
The research team targets 15% CZTS efficiency by next year, with commercialization expected by 2030
Researchers at UNSW (the University of New South Wales) Sydney have set a new record for kesterite (CZTS) solar cell efficiency, achieving 13.2%. This surpasses the previous record of 11.4% and highlights the potential of CZTS technology, a material composed of earth-abundant, non-toxic elements (copper, zinc, tin, and sulfur).
Led by Professor Xiaojing Hao, Dr. Kaiwen Sun, and Dr. Jialiang Huang, the Australian team has addressed kesterite cell material defects, a major challenge in its performance. By annealing (heat-treating) the solar cells in a hydrogen-containing atmosphere, the team has successfully reduced defects through passivation, significantly enhancing the material's ability to convert sunlight into electricity.
This achievement brings CZTS closer to its theoretical efficiency limit, making it a promising candidate for commercialization. Researchers aim to achieve 15% efficiency within a year and potential market readiness by 2030. CZTS is also being considered for tandem solar cells when combined with silicon, a pairing that could exceed the efficiency limits of standalone silicon panels.
"Producing CZTS involves heating copper, tin, zinc, and sulfur, but managing defects is key. Our study reveals that hydrogen passivates these defects, improving the material's ability to convert sunlight into electricity," says Scientia Professor Xiaojing Hao.
Along with CZTS cells, the research team is also exploring perovskite solar cells for tandem applications. While perovskite is known for its high efficiency potential, the researchers point out that CZTS offers significant advantages over perovskites, including environmental friendliness, material abundance, and long-term stability.
In 2020, Prof. Hao was the recipient of the Malcolm McIntosh Prize for Physical Scientist of the Year in recognition of her research work in the field of non-toxic thin-film solar cells (see State honor For Australian Thin Film Solar Researcher).