In two research papers published in the prestigious Joule and PNAS (Proceedings of the National Academy of Sciences), an international research team led by Monash University has developed a highly efficient ultra-thin photovoltaic cell with the highest mechanical Bending and stretching capabilities, and the ability to provide lasting power.
In the Joule paper, the researchers successfully developed a new type of mechanically strong light-absorbing material that can make ultra-flexible solar cells. These batteries can achieve a power conversion efficiency of 13%, maintain an efficiency of 97% after 1000 bending cycles, and maintain an efficiency of 89% after 1000 stretching cycles.
Dr. Wenchao Huang, a researcher from the Department of Materials Science and Engineering at Monash University, said that the power conversion efficiency takes into account how much solar energy can be converted into electrical energy. The solar energy irradiated on the earth is 1000 watts per square meter. Our equipment can generate 130 watts of electricity per square meter. The 13% efficiency that we can achieve is one of the highest in organic solar cells.
In the PNAS paper, tests have shown that after a special method is used to treat the solar cell, its performance only drops by 4.8% after an astonishing 4736 hours. It can run for more than 20,000 hours (about 2.5 years) with minimal degradation. The estimated shelf life is 11.5 years.
The solar cell has an area of only 2 square centimeters, which is roughly the same as Australia’s 5c. It is light enough to be supported by petals and can generate 9.9 watts of power per gram.
After further testing, this revolutionary device can be used as a battery replacement in many future technologies, such as mobile phones, watches, Internet of Things (IoT) and biosensors.
Researchers from RIKEN in Japan co-hosted these studies with collaborators from the University of Tokyo, the University of California, the Australian Synchrotron and Monash University. Researchers are working hard to commercialize the technology.
According to the micro-lithium battery group, researchers have developed new materials and a simple post-annealing method to improve the mechanical and environmental stability of organic photovoltaics without reducing efficiency, thereby improving stability and scalability. Annealing is a heat treatment that can change the physical (and sometimes chemical properties) of the material to reduce its degradation. These solar cells are manufactured and tested in Japanese laboratories using advanced thin film deposition and characterization equipment. Some key parts of this research on device physics were conducted in the Renewable Energy Laboratory at Monash University and the Australian Synchrotron.
The micro-lithium battery team analyzed that despite the small size of this ultra-thin photovoltaic cell, its low-cost characteristics can still be easily replicated by continuous printing technology, which makes it an ideal choice for fast-tracking and mass production of wearable technology.