Heliatek breaks efficiency record for 40% transparent organic cells


Germany’s Heliatek GmbH has this week announced a new world record in transparent organic solar cell efficiency, achieving 7.2% efficiency on solar cells with a 40% light transparency.

The organic solar film company – which already holds the world record for non-transparent organic solar cells at 12% efficiency – has been working on a higher conversion for transparent cells for some time, and believes this latest breakthrough could help transform the building integrated PV (BIPV) industry.

"The transparency of our products is at the core of our market approach," said Heliatek CEO Thibauld Le Seguillon. "Our HeliaFilm is customized to meet our partners’ specific needs. We are a component supplier and this component is a film that can combine transparency and energy generation. This unique combination widens our market potential."

The company’s patented HeliaFilm can be applied to tinted glass and has been pitched at the car roof industry as a way to generate solar electricity and enable car manufacturers to meet ever more-stringent eco-innovation credentials and lower C02 emissions. For the BIPV industry, near-transparent glass panels and windows that have the HeliaFilm applied will also be able to discreetly generate solar PV power when integrated into any building façade.

Although lower than the 12% efficiency generated in opaque cells, the 7.2% achieved is a world record. Partial transparency allows the usage of just 60% of the light for energy harvesting, so for 40% transparent cells this breakthrough represents quite a leap forward for the technology.

Testing was carried out under standard test conditions using a white background, and Heliatek say that the balance between light diffusion and electricity generated can be adjusted, which adds further possibilities for the product’s future use.