An international research team has developed what it describes as the first high-performance, commercially sized tandem solar cell that does not rely on indium, a metal that is scarce and widely used in electronics manufacturing.
In findings published in Science, the researchers report replacing indium-based oxide with tin oxide, an abundant material they say costs about one per cent as much as indium, while maintaining performance.
The work aims to address a potential materials bottleneck for scaling next-generation perovskite tandem solar cells, which are designed to generate more electricity from the same amount of sunlight than conventional silicon-only panels.
Professor Yuan Cheng from Monash Suzhou and Monash’s Department of Materials Science and Engineering said the milestone demonstrates that large-area, highly efficient indium-free perovskite tandem solar cells can be produced beyond laboratory-scale devices.
“Considering the cost of tin is a mere one per cent of that of indium, this breakthrough unveils a new material paradigm and a highly viable engineering route for low-cost, sustainable, and scalable tandem photovoltaics,” Professor Cheng said.
“Ultimately, this work is of paramount strategic importance for propelling the industrialisation and terawatt-scale deployment of next-generation ultra-high-efficiency photovoltaic technologies.”
According to the release, the team used a low-damage reactive plasma deposition process to apply tin oxide, reporting a certified efficiency of 31 per cent in a commercially sized mini-module and improved durability.
The researchers said the devices withstood heat and humidity and operated outdoors for more than three months while maintaining strong performance.
Professor Cheng said the team achieved a certified efficiency of 33.6 per cent on a 1 cm2 device using tin oxide films as a recombination layer, and then scaled the approach to a 207.9 cm2 mini-module with a certified efficiency of 31.0 per cent.
The research was led by a collaborative team including Professor Yuan Cheng (Monash University), Professors Xiaohong Zhang and Xinbo Yang (Soochow University), and Dr Zijia Li (Chint New Energy Technology Co. Ltd), alongside multiple universities and industry participants in photovoltaics.
