New solar cell breakthrough could cut costs and boost clean energy: Ushering in the indium-free era of perovskite/silicon tandem solar cells
An international team of researchers has developed a new way to build high-performance solar cells without relying on indium, a rare and increasingly expensive metal used in many of today's most advanced solar technologies.
The breakthrough replaces indium with tin oxide, a far more abundant and readily available material, without compromising performance.
Published in Science, this research was led by a collaboration team of Professor Xiaohong Zhang and Professor Xinbo Yang (Soochow University (CN)), Professor Yuan Cheng (Monash University), and Dr. Zijia Li (Chint New Energy Technology Co. Ltd), alongside multiple internationally renowned universities and leading enterprises in the photovoltaic industry.
Perovskite/silicon tandem solar cells are widely regarded as the most promising next-generation photovoltaic technology. However, a critical bottleneck impeding their widespread commercialisation is their heavy reliance on indium, which imposes severe constraints on overall production costs.
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 1 cm2. By further extending the application of RPD-SnOx to both the front and rear transparent electrodes, the team successfully fabricated indium-free tandem solar cells.
Remarkably, they scaled this technology up to a 207.9 cm2 mini-module, obtaining an outstanding certified efficiency of 31.0%. This milestone marks the very first realization of a large-area, highly efficient indium-free perovskite tandem solar cell, showing that the technology can be scaled beyond laboratory-sized devices.
Of the research project, Professor Yuan Cheng of Monash Suzhou and Monash Materials Science and Engineering says
"Considering that 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. Ultimately, this work is of paramount strategic importance for propelling the industrialization and terawatt-scale deployment of next-generation ultra-high-efficiency photovoltaic technologies."
As demand for solar energy continues to grow worldwide, reducing reliance on scarce materials is becoming increasingly important. 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 were not only highly efficient but also more durable. The devices withstood heat, humidity and more than three months of outdoor operation while maintaining strong performance.
The advance brings next-generation tandem solar cells a step closer to commercial production, offering the potential for cheaper, more sustainable solar panels that generate more electricity from the same amount of sunlight.
Read the published article in Science here.
