Scientists have managed to convert transparent glass into a photovoltaic surface using a laser similar to those used in eye surgery.
The revolutionary discovery was made by physicists from the Swiss Federal Institute of Technology Lausanne (EPFL) in collaboration with scientists from Tokyo Tech.
Led by Gözden Torun of 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, that formed where the glass was exposed to the laser. The presence of semiconducting materials on a surface exposed to daylight can potentially generate electricity.
Approaching the alchemist’s dream
Yves Bellouard, who leads EPFL’s Galatea Laboratory, said: “We wondered if it would be possible to write durable patterns on the tellurite glass surface that could reliably generate electricity when exposed to light, and the answer is yes.” Bellouard notes that the process does not require additional materials; only tellurite glass and a femtosecond laser are needed to make this active photoconductive material.
The EPFL team used tellurite glass produced by their Tokyo Tech colleagues and applied their expertise in femtosecond laser technology to alter the glass and study the effect of the laser. After etching a simple line pattern on 1 cm diameter tellurite glass and exposing it to UV light and the visible spectrum, Torun discovered that it could generate power consistently for months.
Bellouard expressed his excitement about the breakthrough, saying, “We are locally turning glass into a semiconductor using light. We are essentially transforming materials into something else, perhaps approaching the alchemist’s dream!”
This development could pave the way for windows to function as one-material light collection and detection equipment in the future.
This is not the first time glass has been used to generate energy. Polysolar produces transparent solar panels that “are essentially glass with built-in solar panels”. However, it is not the same because the new technology uses only one material instead of a combination.