Australian PV researchers have made a ‘cool’ discovery: Singlet fission and tandem solar cells – two innovative ways to generate solar power more efficiently – also help lower operating temperatures and keep things running. devices longer.
Tandem cells can be made from a combination of silicon – the most commonly used photovoltaic material – and new compounds such as perovskite nanocrystals, which can have a greater bandgap than silicon and help device to capture a greater part of the solar spectrum for the production of energy.
Singlet fission, on the other hand, is a technique that produces twice as many electronic charge carriers as normal for each photon of light absorbed. Tetracene is used in these devices to transfer the energy generated by the singlet fission into silicon.
Scientists and engineers around the world are working on how best to incorporate tandem cells and singlet fission processes into commercially viable devices that can take over from conventional single junction silicon solar cells found commonly on rooftops and in large-scale networks.
Now, work by the School of Photovoltaic and Renewable Energy Engineering and the ARC Center of Excellence in Exciton Science, both based at UNSW in Sydney, has highlighted some benefits. keys for both tandem cells and singlet fission.
Researchers have shown that silicon / perovskite tandem cells and tetracene-based singlet fission cells will operate at lower temperatures than conventional silicon devices. This will reduce the impact of heat damage on appliances, extending their lifespan and lowering the cost of the energy they produce.
For example, a reduction of 5 to 10 ° C in the operating temperature of the module corresponds to a gain of 2% to 4% in the annual energy production. And it is generally found that the lifespan of the devices doubles for each temperature reduction of 10 ° C. This means an increase in lifespan of 3.1 years for tandem cells and 4.5 years for cells. singlet fission.
In the case of singlet fission cells, there is another practical advantage. When tetracene inevitably degrades, it becomes transparent to solar radiation, allowing the cell to continue to function as a conventional silicon device, even though it initially operated at a lower temperature and provided higher efficiency for the first phase of its life cycle.
Lead author Dr Jessica Yajie Jiang said, “The business value of photovoltaic technologies can be increased either by increasing the efficiency of energy conversion or by increasing the operational lifespan. The former is the main driver of the development of new generation technologies, while little thought has been given. to the potential benefits of lifespan.
“We have demonstrated that these advanced photovoltaic technologies also have ancillary advantages in terms of increased lifespan by operating at lower temperatures and more resilience in the event of degradation, introducing a new paradigm for evaluating the potential of new technologies. solar energy.”
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Material provided by ARC Center of Excellence in Exciton Science. Note: Content can be changed for style and length.