The prestigious Fraunhofer Institute for Solar Energy Systems in Germany (Fraunhofer ISE) together with the Dutch research institute AMOLF have left their mark on the world of solar energy. They developed a multijunction solar cell that achieved a record efficiency of 36.1%, a number never before achieved for silicon-based cells.
A Quantum Leap in Solar Technology
Although silicon is widely used in solar technology worldwide, its efficiency has a natural limit of 29.4%. However, according to the Fraunhofer Institute ISE, there are ways to overcome this ceiling. The secret lies in coating these solar cells with additional materials, transforming them into so-called ‘multijunction’ solar cells.
These new cells have several layers that absorb light, each one dedicated to a specific color of the sun, thus allowing more efficient use.
Albert Polman, project leader for AMOLF, emphasized the importance of the collaboration between the two institutes, which began in 2020, and which resulted in this unprecedented achievement. The combination of specialists in each team is important: while Fraunhofer is recognized for the production of ultra-efficient solar cells based on silicon and semiconductors such as GaInP or GaAs, AMOLF has accumulated experience in optimizing the management of light of solar cells.
Behind the Technology: How was this success achieved?
The record manufacturing used a TOPCon silicon solar cell combined with two semiconductor layers of gallium indium phosphorus (GaInP) and gallium indium arsenide phosphorus (GaInAsP) developed by Fraunhofer ISE. This assembly is subsequently coated with a special metal/polymer nanocoating designed by AMOLF and manufactured in collaboration with Fraunhofer ISE.
An additional element is the rear reflector of the solar cell, which improves the collection of light inside the cell, allowing it to exceed 36% efficiency for the first time.
What is the future of this innovation?
While these ultra-modern solar cells may have higher costs, the Fraunhofer ISE Institute sees great potential in areas with limited space where a large amount of solar energy needs to be can be done in small areas.
The future applications are many, from solar-powered electric cars, consumer electronics, to drones.
Frank Dimroth from Fraunhofer ISE celebrated the success and highlighted the contribution of the new AMOLF rear reflector and the improved Fraunhofer GaInAsP cell to this remarkable result.
Undoubtedly, this development opens a new chapter in the history of solar energy and how we can exploit it for a more sustainable world.