Heliatek GmbH (Dresden, Germany) has developed 1.1 cm² tandem cells manufactured with a low temperature deposition process that have an efficiency of 9.8 %, a new world record for organic solar cells. The percentage was measured and certified by the independent Fraunhofer ISE CalLab (Freiburg, Germany) under standard test conditions.
Heliatek used synthesized materials to optimize the absorber layer system of the cells. By enhancing the deposition process, cell morphology improves, leading to an increase in power output and fill factor. The organic solar cells have doped transport layers. With patented tandem cell technology —two solar cells stacked on top of each other— it is possible to absorb a broad solar spectrum using thin organic layers, altogether only 500nm. The solar cells do not contain any known toxic ingredients or heavy metals.