Printed Solar Cells: Capturing Sunlight on Paper

The cost of energy generated by solar power has drastically declined over the past 40 years due to new technologies and efficiency improvements. The latest invention in this field comes from Aalto University and Swiss Federal Institute of Technology in Lausanne. Their scientists recently developed a simple printing process that allows to print pictures able to generate power.

solar cells

The cost of energy generated by solar power has drastically declined over the past 40 years due to new technologies and efficiency improvements. The latest invention in this field comes from Aalto University and Swiss Federal Institute of Technology in Lausanne. Their scientists recently developed a simple printing process that allows to print pictures able to generate power.

Janne Halme and his colleagues just need an image file to print solar cells in any pattern on any material – even on paper. The professor says that the biggest challenge was to find a solvent for photovoltaic ink that prints in high-quality. The search was now successful: The photovoltaic cells reach an efficiency grade of 20.5 percent. Thanks to this discovery it will soon be possible to integrate solar cells into the visual design of products.

Thin, thinner, solar cells

At the beginning of 2016 engineers from Massachusetts Institute of Technology (MIT) created the world’s thinnest and lightest solar cell. It weighs so little that it can be put on a bubble without bursting it. After all the photovoltaic cell’s weight is 50 times thinner than a human hair.

Therefore Vladimir Bulović, MIT’s associate dean for innovation, sees great potential for their use in applications where weight is important, e. g. on spacecrafts. Since these solar cells are furthermore highly flexible they can be placed on almost any material such as textile – or paper. Additionally their power-to-weight ratio is among the highest ever achieved. That makes them 400 times more efficient than common photovoltaic cells on glass substrates.

First steps to printed solar cells

This is not the first time Bulović researches the printing of solar cells. 5 years ago he and his colleagues have already transformed a simple sheet of paper into a functioning photovoltaic cell. Therefore they have used an evaporating technology that is similar to the procedure for silver coating chips bags. In total they have deposited 250 solar cells on a 7 centimeter square. Those photovoltaic cells were able to produce enough power for 6000 hours. Moreover they are foldable into many shapes.

Also the Institute for Print and Media Technology of Chemnitz University of Technology has presented photovoltaic cells that can be printed on standard paper. This technology using ink with electrical properties is called 3PV, which is short for printed paper photovoltaics.

All these approaches show that the demand for cost-efficient printed solar cells is high. But what do you think? Will photovoltaic cells out of an inkjet printer someday be commercially viable?