Brisbane Materials of Australia has recently developed a 110-nm thick anti-reflection coating with refractive index of 1.25 that they claim to be the most cost-effective and highest performing coating to date, improving a photovoltaic cell’s efficiency by as much as 3%.
Anti-reflection coatings are applied on top of solar cells’ glass cover, which protects them from environmental damages, in order to indulge them of harvesting all photons available for optimum energy conversion. These coatings, as the name implies, hinder reflection of sun’s rays from the surface of solar cells, confining them beneath for higher energy conversion.
Brisbane Materials’ secret to improving the anti-reflection coating is to achieve the right coating thickness and index of refraction optimum for reduction of reflection due to a difference in refractive indeces between the glass cover (1.5) and air (1.0). As per their computation, the optimum dimension is 110nm and the refractive index should be the average of the glass cover and air, that is, 1.25.
Brisbane Materials’ anti-reflection coating is a porous film, shown in the SEM image above, made up of graded refractive index silica that can be applied on plastics or glass via low-cost liquid deposition at room temperature and atmospheric pressure.
The new coating boasts of its superb properties – superhydrophilicity, excellent angular and spectral band width, high durability and service life, and high anti-reflection.With these properties comes the 75% reduction of solar energy losses. What’s more, the coating uses safe and low toxicity materials.
Meanwhile, the battle for higher efficiency and lower costs continues on.