Declining oil prices, supply issues, and dwindling financing may have battered solar energy in recent months, but the industry seems to have sparred well in the research arena. An assortment of institutions separately announced breakthroughs in their quests to boost the efficiency of solar cells. The technological advancements ranged in approach, from the development of an antireflective coating to the formulation of more efficient solar cell materials, but all point to promising possibilities for the industry.
Super-Absorbent Antireflective Coating
In November, researchers at New York’s Rensselaer Polytechnic Institute said they had discovered and demonstrated a new antireflective coating that boosts the amount of sunlight captured by solar panels by allowing the panel to absorb the entire solar spectrum from nearly any angle.
The project, funded by the Department of Energy and the U.S. Air Force, involved stacking seven layers of antireflective coating — each with a height of 50 nanometers to 100 nanometers — in such a way that each layer enhances the antireflective properties of the layer below it (Figure 5). The seven layers were made up of silicon dioxide and titanium dioxide nanorods positioned at an oblique angle, and the nanorods were attached to a silicon substrate via chemical vapor disposition. The additional layers also help to "bend" the flow of sunlight to an angle that augments the coating’s antireflective properties so that each layer not only transmits sunlight, it also helps capture any light that may have otherwise been reflected from the layers below it.
5. Antireflective coating. A new antireflective coating developed by researchers at Rensselaer Polytechnic Institute could help to overcome two major hurdles blocking the progress and wider use of solar power. The nanoengineered coating, pictured here, boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire spectrum of sunlight from any angle, regardless of the sun’s position in the sky. Courtesy: Rensselaer/Shawn Lin
According to results published in the journal Optics Letters, the coating absorbed 96.21% of sunlight shone upon it — compared to the 67.4% of sunlight absorbed by an untreated silicon solar cell. The huge gain in sunlight absorption was consistent across the entire spectrum, from ultraviolet to visible light and infrared.
The new coating also tackles the tricky challenge of angles: If not optimally positioned, conventional solar panels absorb considerably less light, which is why some solar arrays are mechanized to move slowly throughout the day. But, the antireflective coating demonstrated absorption of 96.21% of sunlight evenly and equally from all angles, no matter the position of the sun in the sky, the researchers said. The coating is designed to be affixed to nearly any photovoltaic materials for use in solar cells, including III-V multi-junction and cadmium telluride.
Email
Comments
Print
Reuse
