How to resolve AdBlock issue? Monash Uni’s solar panel tech uses tin oxide at 1% the cost of scarce indium
AN INTERNATIONAL researche team lead by Australia’s Monash University has built the first high-performance, commercially-sized tandem solar cell – and this technology no longer relies on the scarce and expensive metal, indium.
Published in Science, the breakthrough replaces indium-based oxide with abundant tin oxide, a material that costs 1% as much, without sacrificing performance.
The advance brings next-generation tandem solar cells a step closer to commercial production, offering the potential for cheaper solar panels that generate more electricity from the same amount of sunlight. 
Professor Yuan Cheng from Monash Suzhou and the Department of Materials Science and Engineering at Monash said the milestone marks the first realisation of a large-area, highly efficient indium-free perovskite tandem solar cell, showing that the technology can be scaled beyond laboratory-sized devices.
“Considering the cost of tin is a mere 1% 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,” Prof. 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.”
Materials science changes everything
As demand for solar energy continues to grow worldwide, reducing reliance on scarce materials is becoming increasingly important, according to Monash reports.
Indium is used in a wide range of electronics, and its limited supply presents challenges for large-scale manufacturing.
By replacing indium with tin oxide using a low-damage reactive plasma deposition process, the researchers created solar cells that achieved a certified efficiency of 31% in a commercially sized mini-module while also improving durability.
The devices also withstood heat, humidity and more than three months of outdoor operation while maintaining strong performance.
Prof. Cheng said achieving more than 30% efficiency in a commercially sized tandem module is a major technical milestone, and demonstrates that high performance can be maintained without relying on scarce, high-cost materials.
Amazing efficiency realised by innovation
“The research team developed a reactive plasma deposition (RPD) process for tin oxide (SnOx) films to serve as the recombination layer, achieving a remarkable certified efficiency of 33.6% on 1cm2 (one square centimetre),” Prof. Cheng said.
“By further extending the application of RPD-SnOx to both the front and rear transparent electrodes, we successfully fabricated indium-free tandem solar cells. Remarkably, we scaled this technology up to a 207.9cm2 mini-module, obtaining an outstanding certified efficiency of 31%.”
The research was led by a collaborative team including Prof. Yuan Cheng (Monash University), professors Xiaohong Zhang and Xinbo Yang (Soochow University), Dr Zijia Li (Chint New Energy Technology Co. Ltd), with multiple renowned universities and leading enterprises in the photovoltaic industry.
The Science research paper is available at: https://www.science.org/doi/10.1126/science.aef5355
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