Transparent Solar Cells
Transparent solar materials can be used in windows to harvest solar energy. Gargantuan amounts of solar energy can be milked this way, which is greater than that harvested using heavier solar panels on roof tops. The same technology can be used on car windows, skyscrapers, and even cell phones with a clear surface, as covert solar harvesting arrays, seamlessly deployed as a coating, without effecting its aesthetic appearance or its functionality.
Transparent photovoltaics, whose solar cells are invisible and allows visible light transmission, could be used primarily to absorb the invisible wavelengths of light like ultraviolet and infrared, and then convert that absorbed energy into electricity. Although the efficiency of such a system, is just 5%, compared to their opaque or translucent counterparts which have an efficiency of 18%. Complementary deployment of both these technologies would be the best way.
Transparent photovoltaics are basically composed of organic molecules. By modifying the organic molecule layer, it is ensured that the reflectivity is reduced, with an increase in photon harvesting capacity. Non-periodic photonic crystals can be used for this purpose. Essentially, the coating consists of absorptive semiconductor materials which create an electric field when excited by photons, the absorptive materials sit between electrodes that carry the current out of the device. With the right combination of materials, transparent solar cells could be applied as a thin coating on various surfaces, while still maintaining the ability to transmit at least 90% of the light, by reducing reflection — using anti-reflection coatings. Designing such a concealed solar cell, needs finesse and utmost care. For instance, if infrared wavelength is blocked this could save air conditioning energy costs, in tropical zones.
Transparent solar materials are still in their nascent stage, and more needs be done to fully realize its innate potential. If this innovative technology can be used on all the unexplored surfaces, it would be groundbreaking. Continual development work to improve the efficiency of unseen solar cells, using several materials is under way. After all, hidden solar cells could turn many devices into power generators.
© 2017 Rayan Milkton