Scientists have successfully converted transparent glass into a photovoltaic surface using a laser similar to that used in eye surgeries.
The revolutionary discovery was made by physicists at the Swiss Federal Institute of Technology Lausanne (EPFL) in collaboration with scientists from Tokyo Tech.
Led by Gözden Torun at the Galatea Lab, the researchers were intrigued to see how tellurite glass would react when exposed to femtosecond laser light. This curiosity led to the unexpected discovery of nanoscale tellurium and tellurium oxide crystals, both semiconducting materials, forming where the glass was exposed to the laser. The presence of semiconducting materials on a surface exposed to daylight could potentially generate electricity.
Approaching the dream of the alchemist
Yves Bellouard, who heads EPFL’s Galatea Laboratory, said, “We wondered if it would be possible to write durable patterns on the tellurite glass surface that could reliably induce electricity when exposed to light, and the answer is yes.” Bellouard notes that the process requires no additional materials, only tellurite glass and a femtosecond laser are needed to create this active photoconductive material.
The EPFL team, using tellurite glass produced by their Tokyo Tech colleagues, applied their expertise in femtosecond laser technology to alter the glass and study the laser’s effect. After etching a simple line pattern onto a 1 cm diameter tellurite glass and exposing it to UV light and the visible spectrum, Torun found it could generate a current consistently for months.
Bellouard expressed his excitement at the breakthrough, saying, “We’re locally turning glass into a semiconductor using light. We’re essentially transforming materials into something else, perhaps approaching the dream of the alchemist!”
This development may pave the way for windows to function as single-material light-harvesting and sensing devices in the future.
This isn’t the first such time glass has been used to generate energy. Polysolar manufactures transparent solar panels that “are essentially glass with solar panels built into them”. It’s not the same however, as the new technology uses just one material, rather than a combination.
