New Australian research pushes solar energy generation closer to a paint-on PV solution.

 

Griffith University researchers have discovered new potentials for light harvesting which may allow the design of a new class of composite materials for light harvesting and optoelectronics.

The researchers for the first time have found a quantum-confined bandgap narrowing mechanism where UV absorption of the graphene quantum dots and TiO2 nanoparticles can easily be extended into the visible light range.

Dr Qin Li, associate professor in the Environmental Engineering & Queensland Micro- and Nanotechnology Centre, says real life application of this would be high efficiency paintable solar cells and water purification using sun light.

“This mechanism can be extremely significant for light harvesting,” Dr Li said. “What’s more important is we’ve come up with an easy way to achieve that, to make a UV absorbing material to become a visible light absorber by narrowing the bandgap.”

Visible light makes up 43 per cent of solar energy compared to only 5 per cent possessed by UV light.

Major efforts have been made to improve titania’s absorption of visible light or develop visible-light sensitive materials in general.

In their paper published in Chemical Communications, a Royal Society of Chemistry journal, the researchers observed that when TiO2 particles are mixed with graphene quantum dots, the resulting composite absorbs visible light by a quantum-confined bandgap narrowing mechanism.

“When two UV absorbing materials, namely TiO2 and graphene quantum dots, were mixed together, they started to absorb in the visible range, more significantly, the bandgap can be tuned by the size of graphene quantum dots,” Dr Li said.

 

From the Griffith University Newsroom, “Researchers uncover new light harvesting potentials” by  July 14, 2016.