Scientists at Rice University in Texas have created an atom-thick material that can assist in the development of ultra-thin imaging devices.
Sidong Lei, a graduate student, and his team created copper indium selenide (CIS), which is a single-layer grid of copper, selenium and indium atoms. Lei made a prototype, which is a three-pixel, charge-coupled device (CCD), to determine the material's capability to catch an image.
According to the researchers, the optoelectronic memory material may become a significant component in 2D devices that capture pictures. Old-fashioned CCDs are normally rigid and thick, and there is no sense in combining CCDs with 2D elements.
CCDs that are based on CIS, however, will be flexible, transparent and ultra-thin, which may be highly preferred in 2D imaging devices.
Electrons are formed by the device when the atom-thick material is hit by light and holds on to them until they are freed for storage.
Robert Vajtai, a faculty fellow at Rice University's Department of Materials Science and NanoEngineering, says that CIS pixels have high sensitivity to light as the electrons dissipate slowly. Currently, there are 2D materials that can sense light; however, none of the existing materials are as efficient when compared to the latest material.
"This material is 10 times more efficient than the best we've seen before," said Vajtai.
The transparent property of the material will enable scanners based on CIS to utilize light from just one end to illuminate an image and capture it. Lei believes that CIS can be combined with existing 2D electronics in bio-imaging devices that monitor real-time situations.
Lei explains that they grew CIS crystals then extracted a single-layer sheet from them. The experiment helped the researchers test the layers' ability of capturing light. The atom-thick layer is around two nanometers in thickness and comprises of a nine-atom-thick lattice. Lei suggests that the growth of the material can also take place via chemical vapor deposition to a size that is restricted only by the furnace's dimensions.
The flexibility allows CIS to be curved so that the imaging lens system's focal surface and the CIS match.
The study was published in the journal Nano Letters.
