New research led by an Indian origin professor in the U.S heralds the day when one can apply a coat of paint on the outside walls of a house to generate electricity from sunlight that can be used to power the appliances and equipment on the inside.
The team of researchers at the University of Notre Dame in the U.S has developed an inexpensive "solar paint" that uses semiconducting nanoparticles to produce energy.
"By making use of recent advances in semiconductor nanocrystal research, we have now developed a one-coat solar paint for designing quantum dot solar cells," Kamat and co-workers said.
The researchers said they wanted to do something transformative, to move beyond current silicon-based solar technology.
"By incorporating power-producing nanoparticles, called quantum dots, into a spreadable compound, we've made a one-coat solar paint that can be applied to any conductive surface without special equipment."
According to the researchers, their paint is based on nano-sized particles of titanium dioxide coated with either cadmium sulfide or cadmium selenide. Describing the work they said the particles were suspended in a water-alcohol mixture to create the binder-free paste which was then applied to conducting glass surface and annealed at 200 degrees C.
"When the paste was brushed onto a transparent conducting material and exposed to light, it created electricity."
This paste of nanoparticles when applied on surfaces using simple conventional paint brush "could turn large surfaces into solar cells", says a statement by the Notre Dame University.
The best light-to-energy conversion efficiency reached so far is 1 percent, which is much less than the usual 10 to 15 percent efficiency of commercial silicon solar cells. "But this paint can be made cheaply and in large quantities," the researchers claim.
"If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future."
"Whereas further improvements are necessary to develop strategies for large area, this initial effort to prepare solar paint offers the advantages of simple design and economically viable next generation solar cells," the researchers said.
Kamat and his team also plan to study ways to improve the stability of the new material.