Good news for solar power as the University of New South Wales ARC Photovoltaic Centre of Excellence has announced that they managed to develop a silicon solar cell which has an efficiency of 25 percent. It’s a new world record, however, the previous record was also held by the UNSW ARC Photovoltaic Centre of Excellence with an efficiency of 24.7 percent.

A team led by Professors Martin Green and Stuart Wenham revised and tweaked a little their silicon solar cell, the UNSW ARC Photovoltaic Centre of Excellence managed to achieve one of their six new world records and they say that this was possible thanks to their knowledge about sunlight.

“Since the weights of the colors in sunlight change during the day, solar cells are measured under a standard color spectrum defined under typical operational meteorological conditions,” said Professor Green who is also the Centre Executive Research Director.

“Improvements in understanding atmospheric effects upon the color content of sunlight led to a revision of the standard spectrum in April,” he added. “The new spectrum has a higher energy content both down the blue end of the spectrum and at the opposite red end with, dare I say it, relatively less green.”

In theory, the first-generation of silicon solar cells could reach a maximum of 29 percent efficiency and Dr Anita Ho-Baillie, leader of the high efficiency cell research at the UNSW ARC Photovoltaic Centre of Excellence, said that this is possible “because our cells push the boundaries of response into the extremities of the spectrum.”

“Blue light is absorbed strongly, very close to the cell surface where we go to great pains to make sure it is not wasted. Just the opposite, the red light is only weakly absorbed and we have to use special design features to trap it into the cell,” continued Dr Ho-Baillie.

According to Professor Green, their silicon solar cells are so good thanks to their “light-trapping features” which “make our cells act as if they were much thicker than they are. This already has had an important spin-off in allowing us to work with CSG Solar to develop commercial ‘thin-film’ silicon-on-glass solar cells that are over 100 times thinner than conventional silicon cells.”

“Our main efforts now are focused on getting these efficiency improvements into commercial production. “Production compatible versions of our high efficiency technology are being introduced into production as we speak,” added Professor Stuart Wenham, ARC Centre Director.

For the moment, we don’t know when these type of silicon solar cells will be integrated in solar panels, however, we expect this to happen as soon as they are cheaper to manufacture.