Magnolia Solar Corp. reported that a glass window coated with a porous silicon dioxide nanostructure coating produces an “ultra-high, omnidirectional transmittance” over the entire accessible portion of the solar spectrum.
A report on the technology, presented by Magnolia’s chief technical officer, Dr. Roger E. Welser, at the IEEE Photovoltaics Specialist Conference (PVSC), noted that the nanostructured coating for photovoltaic applications “significantly outperforms conventional magnesium fluoride coatings at all relevant wavelengths and incident angles.”
The presentation was part of a special session on New Concepts in Light Concentration and Light Trapping, and summarizes work done in collaboration with NYSERDA and Prof. Fred Schubert's group at the Rensselaer Polytechnic Institute (RPI).
“Ultra-high, broadband transmittance through coated glass windows has been demonstrated over a wide range of incident angles,” Welser said. “At normal incidence, the reflection losses at the glass-air interface have been reduced from approximately 4% to less than 1%. At large angles of incidence, the reflection losses have been reduced from over 25% to less than 5%.”
Dr. Ashok K. Sood, president and CEO of Magnolia Solar, said, “The antireflection technology described at the IEEE-sponsored conference can increase the power output of any photovoltaic module, including crystalline-silicon and thin-film technologies, by reducing the reflection losses.”
He said that fixed, flat-plate solar-cell modules generally suffer significant reductions in power output due to reflection off the front glass encapsulant, especially when light strikes the panel at glancing angles (most severe in the early morning and late in the afternoon).
“Nanostructured optical coatings can increase the power output of fixed, flat-plate modules by minimizing reflection losses throughout the day,” Sood said.
The patent-pending technology has the potential to benefit a wide variety of specialized military and commercial optical window applications.
The company is currently focused on developing a larger-scale process for the deposition of nanostructured optical coatings.
Based in Woburn, Mass. and Albany, N.Y., Magnolia Solar was founded in 2008 to develop and commercialize new thin-film solar-cell technologies that employ nanostructured materials and designs.
More information: www.MagnoliaSolar.com.