Researchers from Duke University have created silver nanocubes that have the ability to absorb an incredible amount of light. This new technology has shown great potential for use in solar panels, potentially leading to more efficient and cost-effective absorbers for solar cells.
The silver nanocubes are a meta-material, which means that they are a human-created material designed specifically to have traits that are not present in natural materials. They can be designed to allow great control over waves, such as light. The manufacture of materials like this has remained something of a challenge, though. The method usually used, lithography, is expensive and doesn’t scale well.
“Our new approach is more of a bottom-up process,” said Cristian Ciracì, research scientist at Duke’s Pratt School of Engineering. “It may allow us to create devices — such as efficient solar panels — that cover much larger areas. In our experiments, we demonstrated an extraordinarily simple method to achieve this.”
The new material is composed of three main components; a thin gold film layer that’s then coated with a nano-thin layer of an insulator and then dusted with self-assembled nanocubes numbering in the millions. Currently, the researchers are using nanocubes fabricated from silver.
“The nanocubes are literally scattered on the gold film and we can control the properties of the material by varying the geometry of the construct,” Ciracì said. “The absorptivity of large surface areas can now be controlled using this method at scales out of reach of lithography.”
Though metals are reflective when on their own, “the nanocubes act as tiny antennae that can cancel out the reflectance of the metal surface.”
“By combining different components of the metamaterial elements together into a single composite, more complicated reflectance spectra could be engineered, achieving a level of control needed in more exotic applications, such as dynamic inks,” Ciracì said.
The new creation was just detailed in a paper published December 6th in the journal Nature.
Source: Duke University
Image Credits: Cristian Ciraci
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