European thin film solar cell research institute Solliance has recently developed a tandem solar cell of an ultra-high efficiency, which is formed with perovskite solar and silicon crystal. It is capable of achieving a conversion efficiency of up to 29.2%.
Solliance, the Netherlands Organization for Applied Scientific Research (TNO), EnergyVille, and Eindhoven University of Technology, are convinced that the new tandem solar technology is able to increase conversion efficiency. The new tandem cell is adopted with 4 terminals (4T), where the two batteries on both upper and lower parts are independently connected, instead of the traditional 2-terminal structure that is concatenated between the upper and the bottom.
Solliance has been studying tandem cells for a while now, and managed to create a tandem module that has a conversion efficiency of 28.7% in April, though it may take some time for additional breakthroughs. Gianluca Coletti, Program Manager of PV tandem technology and applications at TNO, commented that the wide energy gap of perovskite cells allows near infrared light to penetrate, which helps to increase the conversion efficiency.
The transparent perovskite solar utilized by the team attained a conversion efficiency of 17.8% under 5 minutes of maximum power point tracking. The team then combined the Panasonic crystal silicon cell with the transparent perovskite cell, which yielded a new world record of 29.2% in the concatenated efficiency of 4T perovskite-silicon. Coletti believes that this 4T cell can be used in large public solar power plants and commercial rooftop solar in the future.
The research team also concatenated perovskite cell with thin film solar, which achieved a relatively satisfying result at the end as well, as an efficiency of 27.1% was attained in the 2T perovskite-CIGS cell after concatenation with CIGS made by MiaSolé Hi-Tech.
(Cover photo source: Flickr/David Goehring CC BY 2.0)