2-D materials' crystalline defects key to new properties

Wednesday, September 24, 2014

Understanding how atoms "glide" and "climb" on the surface of 2D crystals like tungsten disulphide may pave the way for researchers to develop materials with unusual or unique characteristics, according to an international team of researchers.

"If we don't understand what is behind the materials' characteristics caused by these defects, then we can't engineer the right properties into devices," said Nasim Alem, assistant professor of materials science and engineering, Penn State. "With a closer look, we might find that some of the defects are no good, that we don't want them in our materials, but we need to understand the defects first."

Tungsten disulphide as a 2D crystalline material is a semiconductor, so it can be used in electronic devices and it is also a catalyst used to liberate hydrogen gas from compounds. The defects or dislocations occur when an atom is displaced from the regular, repeated pattern of atoms in the crystal.