‘Solar’ nanocrystals are about 4 nanometers – that means you could fit more than 250 billion on a pinhead – and float in a liquid solution, “so that, as a printed newspaper, you can also print solar cells,” said Richard L. Brutchey, assistant professor of chemistry at the Dornsife College of Letters, Arts and Sciences at USC.
R. Brutchey and David H. Webber developed a new coating nanocrystal, which is made of semiconductor cadmium selenide. Their research was presented this month in the international journal of inorganic chemistry “Dalton Transactions”.
The liquid nanocrystal solar cells are cheaper to manufacture than those designed using monocrystalline silicon wafers, but remain less efficient at converting sunlight into electricity. The two researchers also solved a key problem in solar cell manufacturing liquid: “how to create a stable liquid that leads also generate electricity?”
In the past, organic molecules (ligands) were related to the nanocrystals to maintain some stability and especially to prevent them from clumping. These molecules also rattled the crystals, which made the thing terribly complicated in terms of electrical conductivity. “It remained a challenge in this area,” said Professor R. Brutchey.
The two acolytes have therefore discovered a ‘ligand’ synthetic that not only plays a role in stabilizing the nanocrystals, but is applied to create small bridges connecting the nanocrystals them, helping in turn to conduct current.
In a low temperature process, the method would also allow researchers to print solar cells on plastic instead of glass without encountering the problem of merger – which would give a flexible solar panel mouldable and adaptable at will anywhere .
In continuation of their research, R. Brutchey always said it planned to work on nanocrystals based from materials other than cadmium, which is limited commercially due to its toxicity. “While the commercialization of this technology is still remote, we see a possible integration into the next generation of solar cells,” he has said in conclusion.