The Japanese research institute RIKEN has developed an organic solar cell that can be stretched up to 1.5 times its original length while losing less than 20% of its initial efficiency
Elastic Photovoltaics: Towards a Greener and More Flexible Future
A stretchable polymer solar cell, like an elastic film but with high performance, capable of maintaining its ability to convert light into electricity even when stretched. This is the innovation developed by a group of physicists from Japan’s RIKEN Institute. The device, currently still in the laboratory phase, has achieved one of the most promising results in the field of “stretchable” electronics. When tested, the new elastic organic photovoltaic demonstrated an initial conversion efficiency of 14.2%, exceptional elasticity, and record-breaking mechanical durability in cyclic stretching.
The New Frontier of Wearable Electronics
In recent years, studies on soft batteries and elastic solar cells have increased exponentially. Why? Because wearable electronics have become one of the major trends in high-tech, and with it, the demand for energy sources that can be safely integrated into such devices has grown.
In this field, intrinsically stretchable organic photovoltaics have emerged as a standout solution for next-generation wearable energy generators. The credit goes to the structural flexibility of its design, its omnidirectional elasticity, and its planar deformability.
However, manufacturing solar cells that are both elastic and efficient remains a challenge. The biggest technical obstacle involves the transparent electrode and the fragile active layer.
A New Elastic Polymer Solar Cell
Kenjiro Fukuda from the Center for Emergent Matter Science at RIKEN, along with colleagues, is trying to solve the problem with a new approach. “We use stretchable materials for every functional layer of the device,” says Fukuda.
The key to success was found by delocalizing and redistributing the strain of the active layer to the underlying layers. This step was made possible, unexpectedly, by improving the elasticity of the PEDOTelectrode through the incorporation of an additive, called ION E for short. “It was a pleasant surprise for us,” Fukuda stated. “We didn’t anticipate that ION E would increase adhesion between the layers.”
The research, published in the journal Nature Communications, shows that the elastic polymer solar cell can be stretched up to 1.5 times its original length without a collapse in its initial efficiency. Specifically, it only experiences a drop of about 20%. Furthermore, it retains 95% of its initial efficiency after being stretched 100 times by 10%.
