Latest Developments in Solar Power

Researchers are busy trying to develop solar energy, both in terms of efficiency as well as materials and manufacturing processes.

At the University of Notre Dame, researchers have developed what they call a ‘solar paint’ that could be applied to the exterior of a building to generate electricity, said TG Daily.

They call the solar paint Sun-Believable and although levels of efficiency are low (1 per cent) compared to current standards (around 15 per cent), it’s inexpensive and easy to produce is mass quantities. In order to produce the paint, the researchers used nano-sized particles of titanium dioxide which were then coated with either cadmium sulfide or cadmium selenide. After that, the particles were suspended in a mixture of water and alcohol to create a paste.

Elsewhere, researchers at the University of Florida said they achieved a new record in efficiency with a prototype solar cell that could be manufactured using a roll-to-roll process. They compare the process to printing newspaper roll to roll.

The roll-to-roll manufacturing process is not a new idea. Imagine photovoltaic sheets being applied to the exterior of buildings, cars, clothing and accessories. But so far PV sheets have not mustered enough energy per square inch to make them viable to manufacturers. The UF researchers have managed to cross the critical threshold of eight per cent efficiency in laboratory prototype solar cells, which means the cells could be economically feasible.

They used a specially treated zinc oxide polymer blend as the electron charge transporting material. The full report outlining the details of their latest laboratory success in solar cell technology was published in the December 18 online version of Nature Photonics.

The researchers said the innovative process they used to apply the zinc oxide as a film was key to their success. They first mixed it with a polymer so it could be spread thinly across the device, and then removed the polymer by subjecting it to intense ultraviolet light.

John Reynolds, a UF professor of chemistry working on the project, said the cells are layered with different materials that function like an electron-transporting parfait, with each of the nano-thin layers working together synergistically to harvest the sun’s energy with the highest efficiency.

Reynolds’ chemistry research group developed an additional specialized polymer coating that overlays the zinc oxide polymer blend. His team is aligned in an ongoing collaboration with a material sciences team led by Frank So, a professor at UF’s department of materials science and engineering. They call the partnership “The SoRey Group.”

The most recent fruit of their collaboration will now go to Risø National Laboratory in Denmark, where researchers will replicate the materials and processes developed by the SoRey Group and test them in the roll-to-roll manufacturing process.

Article by Antonio Pasolini, a Brazilian writer and video art curator based in London, UK. He holds a BA in journalism and an MA in film and television.