US scientists use nanoscale structures to lower reflectivity in solar cells

A team of scientists from the U.S. Lawrence Livermore National Laboratory has developed a new anti-reflecting coating to reduce reflectivity in solar cells and optics.

The researchers claim they have been able to lower the reflectivity of silicon optics to as little as 1% by applying layers of hierarchical micro- and nanometer length structures to the surface of the devices.

This new technology, the research team said, is based on the hierarchical structures found in the eye of a moth, which allows them to absorb more light and better navigate in the darkness.

The authors of the study, published in the journal Advanced Optical Materials, said they were able to reduce the average hemispherical or total reflectance of silicon from around 38% to approximately 11% by engineering into the silicon the micro-scale pyramidal structures. “However, by stacking micro- and nano-sized arrays on top of the larger structures, total reflectivity can be reduced to as little as between 1% and 2% regardless of the angle of incoming light,” the scientists stated.

These hierarchical structures were conceived to eliminate reflectivity and glare without producing the green or purple color effect that current anti-reflective glass coatings have.