With the market for wearable electric devices growing rapidly, stretchable solar cells that can function under strain have received considerable attention as an energy source.
To build these solar cells, it is necessary that their photoactive layer, which converts light into electricity, shows high electrical performance while possessing mechanical elasticity. However, satisfying both of these two requirements is challenging, making stretchable solar cells difficult to develop.
Now, a KAIST research team from the Department of Chemical and Biomolecular Engineering (CBE) led by Professor Bumjoon Kim has announced the development of a new conductive polymer material.
This material achieved both high electrical performance and elasticity while introducing the world’s highest-performing stretchable organic solar cells.
The research, ‘Rigid- and soft-block-copolymerized conjugated polymers enable high-performance intrinsically stretchable organic solar cells,’ is published in Joule.
The use of high performance solar cells in wearable devices
Organic solar cells are devices whose photoactive layer, which is responsible for converting light into electricity, comprises organic materials.
Compared to existing non-organic material-based solar cells, they are lighter and more flexible, making them highly applicable for wearable electrical devices.
Solar cells as an energy source are particularly important for building electrical devices, but high-efficiency solar cells often lack flexibility, and their application in wearable devices has, therefore, been limited to this point.
Stretchable solar cells could pave the way for use in electricals
The team conjugated a highly stretchable polymer to an electrically conductive polymer with excellent electrical properties through chemical bonding and developed a new conductive polymer with both electrical conductivity and mechanical stretchability.
This polymer meets the highest reported level of photovoltaic conversion efficiency (19%) using organic solar cells while also showing ten times the stretchability of existing devices.
Therefore, the team was successful in building the world’s highest-performing stretchable solar cell that can be stretched up to 40% during operation and demonstrated its applicability for wearable devices.
Professor Kim explained: “Through this research, we not only developed the world’s best performing organic stretchable solar cell, but it is also significant that we developed a new polymer that can be applicable as a base material for various electronic devices that need to be malleable and/or elastic.”
