Nicholas X. Fang, the Brit (1961) and Alex (1949) d’Arbeloff career development associate professor in engineering design in MIT’s department of mechanical engineering, says that most thin materials used to fully capture light are limited to a very narrow range of wavelengths and angles of incidence. The new design uses a pattern of wedge-shaped ridges whose widths are precisely tuned to slow and capture light of a wide range of wavelengths and angles of incidence.
These metamaterials can be extremely thin, saving weight and cost. Fang compares the tapered structures to the cochlea of the inner ear, which responds to different frequencies of sound at different points along its narrowing structure. ”Our ears separate different frequencies and gather them at different depths,” he says; similarly, the metamaterial wedges harvest photons at different depths.
The actual structure of the material is etched from alternating layers of metal and an insulating material called a dielectric, whose response to polarised light can be varied by changing an electric field applied to the material. The creation of this new material is described in a paper to be published in a forthcoming issue of the journal Nano Letters.
Categories: Alternative energy, Research, Science, Science and Technology, Technology, World
The efficiency rate of photo voltaic cells is about 27%. This is the ratio of amount of power going in vs. power output. Until that ratio improves to over 50% and the price per unit drops to comparable fossil based sources, mass adoption rate would be timid.
Necessity is mother of all inventions. India has lot of hydro and thermal energy plants. But knowing that coal can someday run out of reserves and rivers might dry up in the event of melting of himalayan glaciers/change in monsoon patterns. Socialist structure of India allows governments to provide subsidy/tax benefit for solar energy projects. Gujarat is an leading example to present.
http://www.eai.in/club/users/aathmika/blogs/1074
We can hope and pray that higher efficiency solar photo-voltaic cells will come in the subsequent generations of solar cells or possibly something better than that. If storage batteries can be made further compact and light weight, then one day solar powered all weather cars can become a reality. Jazakh Allah for your comment Sazzad sb.