Solar Cells Thinner Than Spider Silk

Researchers have developed flexible, stretchable polymer-based solar cells on plastic foil substrates thinner than spider silk and able to generate 10 watts per gram.
Cooperation between scientists at the Johannes Kepler University Linz (JKU) in Austria and the University of Tokyo led to the development of the cells, which are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date.  


While not the type of solar cell you would use in traditional solar panels – silicon based PV is still far superior to organic photovoltaics when it comes to efficiency – the development has applications for electronic textiles, synthetic skin and robotics.
“In all of these areas it is important that cells not only be highly efficient, but also light and flexible. There are many areas in which rigid and inelastic cells are inapplicable,” said Dr. Martin Kaltenbrunner, from JKU’s Institute of Experimental Physics.
“The basic system can also be applied to electrical circuitry which would be something that the industrial sector, for example, would take interest in.”
The new cells can attain a 4.2% power conversion efficiency and tensile strains of more than 300% on an elastomeric support, according to the research paper published in scientific journal, Nature Communications.
The image above depicts the bending flexibility of the cell demonstrated by it being wrapped around a human hair with a radius of 35 microns.
The substrate used for the cell is a commercially available form of Mylar 1.4 CW02, a form of PET film. The total device is only 1.9 microns thick and around one-quarter of the thickness is the active solar cell.
Source/image source – Kaltenbrunner, M. et al. Ultrathin and lightweight organic solar cells with high flexibility. Nat. Commun. 3:770 doi: 10.1038/ncomms1772 (2012).