Japanese scientists develop ‘moth eye’ cell film

The PV industry’s latest innovation in cell design owes as much to Mother Nature as it does to time spent in any laboratory. And it is the water-repellent, antireflective coating of a moth’s eye that has provided the inspiration behind this latest advance in thin-film technology.

A Japanese research team has published a paper about its next generation cell protection film which mimics eye microstructure of a moth. Through this it significantly cuts down on the amount of sunlight reflected by the cell thus enables it to harness more of the sun’s solar energy.

"Surface reflections are an essential loss for any type of photovoltaic module, and ultimately low reflections are desired," said Nagaoka University of Technology’s Noboru Yamada, who led a research team that also included scientists from Mitsubishi Rayon and Tokyo Metropolitan University.

The paper published in Energy Express found that the 'moth eye' films improved the annual efficiency of solar cells in their two testing regions of Phoenix and Tokyo by around 6 per cent and 5 per cent respectively.

"People may think this improvement is very small, but the efficiency of photovoltaics is just like fuel consumption rates of road vehicles. Every little bit helps," added Yamada.

The team is currently working on improving the film’s durability and tailoring it for a range of solar cells.