New material has optical applications

UNIVERSITY PARK, Pa., Feb. 4 (UPI) -- A rare mineral called tungstenite has been formed into thin sheets with possible uses in technologies such as light detectors and lasers, U.S. researchers say.

Stacked in sheets with sulfur atoms, it forms tungsten disulfide in a honeycomb pattern of triangles that have been shown to have unusual light-emitting, or photoluminescent, properties, Penn State researchers reported Monday.

Photoluminescence occurs when a substance absorbs light at one wavelength and re-emits that light at a different wavelength, Penn State physics and material science Professor Mauricio Terrones said.

The "monolayer" of tungstenite and sulphur atoms photoluminesce at room temperature, he said, so "no special temperature requirements are needed for the material to exhibit this property."

The researchers said the material has many potential applications in the fields of optical light detection, the production of light-emitting diodes, and even laser technology.

"The images of the photoluminescence are beautiful; the triangles light up all around their edges like little holiday ornaments -- holiday ornaments with potentially transformative, long-term applications in nano-optics," study co-author Vincent H. Crespi said.