Companies have been racing to slim down LEDbacklights as devices get ever thinner, but the University of Washington mayhave just beaten everyone to the finish line. Its scientists have developed anLED that, at three atoms thick, is easily the thinnest LED to date in fact,it"s impossible to build something thinner using current knowledge. The keyingredient is tungsten diselenide, the thinnest known semiconductor. A singlesheet of the material is less than a tenth as thick as a conventional LED, but stillemits measurable light. It"s flexible and strong, too. On a basic level, thetechnology could be handy for optical circuits, nanolasers and other areaswhere miniscule lighting is necessary. However, the researchers also see usesfor their LED in mobile devices it could end up in wearables and othergadgets where even a slight difference in thickness could make a big impact.