Published on November 27th, 2013 | by James Ayre3
High-Power Self-Cleaning Solar Panels Via Nanoscopic Relief Patterns
November 27th, 2013 by James Ayre
Self-cleaning solar cells capable of generating high quantities of electricity may soon be a reality thanks to new findings made by researchers from the Changchun University of Science and Technology, Xi’an Technological University, and Cardiff University.
Two of the great limiters of solar cell conversion efficiency — as experienced in real-world settings — are the inherent reflectivity of the silicon surfaces of the solar modules, and their potential to get dirty. The utilization of new nanoscopic relief patterns addresses both of these issues — applied to the surface of a solar cell, the nanoscopic relief patterns create a non-reflective surface that significantly boosts conversion efficiency, as well as making the solar cells “highly non-sticking” and self-cleaning.
The press release provides more:
Zuobin Wang of Changchun University of Science and Technology (China), Jin Zhang of Xi’an Technological University (China) and colleagues at Cardiff University (UK), who are partners of the EU FP7 LaserNaMi project, have devised an approach to lithography, the process used to “print” microelectronic circuits, that allows them to add a pattern to the surface of a solar cell. The features of the pattern are so small that individual parts are shorter than the wavelength of light. This means that incident sunlight becomes trapped rather than reflected passing on more of its energy to electricity-generation process that takes place within the panel.
The same pattern also makes the surface of the solar cell behave like the surface of a lotus leaf, a natural material that is known to be very water repellant, or hydrophobic, so that particles and liquids that land on it do not become stuck as there is no surface to which the droplets can grip. When it rains any deposits are sloughed away and the rainwater runs off efficiently leaving the panel clean and dry after the downpour.
The work done by the researchers indicates that, by placing a nanoscopic patterned layer on top of the active part of the solar panel, it’s possible to avoid much of the energy loss that’s caused by reflection from the surface. This results in a direct boost to the absorption of sunlight in the visible spectrum, and into the near-infrared part of the spectrum as well.
The researchers suggest that “printing the surface of the photovoltaic cell so that it is covered with nanoscopic cones would provide the optimal combination of making the panel non-reflective and hydrophobic and so self-cleaning.”