Australian Team Breaks Solar Cell Record After 4-Year Plateau

Scientists in Australia just solved a stubborn problem that had blocked progress on an exciting type of solar cell for four years.

Researchers at the University of New South Wales reached a new efficiency record of 11.02% for antimony chalcogenide solar cells, breaking past the 10% ceiling that had stood since 2020. The achievement might sound modest, but it represents a major leap for a technology that could transform how we harvest energy from the sun.

The material at the heart of this breakthrough has some serious advantages. Antimony chalcogenide is abundant, inexpensive, and can be manufactured at low temperatures, making it perfect for large-scale production. These properties make it an ideal candidate for tandem solar cells, where multiple layers work together to capture different parts of the sunlight spectrum.

The UNSW team discovered the problem was surprisingly simple: the elements inside the material weren't mixing evenly during production. Researcher Chen Qian compared it to driving a car up a steep slope instead of on a flat road. The uneven distribution created an energy barrier that trapped electrical charges before they could flow through the cell.

The solution was equally elegant. By adding a small amount of sodium sulfide during production, the team smoothed out the distribution of elements inside the cell. This allowed electrical charges to move freely, converting more sunlight into electricity.

The improvement was verified independently by CSIRO, Australia's national science agency, which certified the efficiency at 10.7%. That might represent the first time this technology has crossed the critical 10% threshold with official verification.

Why This Inspires

This breakthrough shows how persistence pays off in clean energy research. While other teams might have moved on after hitting the same wall for four years, the UNSW group kept investigating until they found the root cause.

Professor Xiaojing Hao, who led the research, emphasized that the world needs multiple options for next-generation solar technology. Each material has different strengths, and antimony chalcogenide's unique properties make it particularly promising for tandem cells paired with traditional silicon.

The team isn't stopping at 11%. They're already working on chemical treatments to reduce remaining defects in the material, with confidence they can reach 12% efficiency in the near future. Each percentage point improvement brings this affordable, abundant material closer to commercial viability.

The future of solar energy isn't just about finding one perfect solution but developing multiple pathways to capture more of the sun's power. This breakthrough adds another strong contender to that race.