Company Develops Lighting Sheets Consisting Of Tiny LEDs.

Technology Review (10/28, Bullis) reported, "Nth Degree Technologies hopes to replace light bulbs with what look like glowing sheets of paper." The company "makes its light sheets by first carving up a wafer of gallium nitride to produce millions of tiny LEDs-one four-inch wafer yields about eight million of them. The LEDs are then mixed with resin and binders, and a standard screen printer is used to deposit the resulting "ink" over a large surface." The article reported that "on addition to the LED ink, there's a layer of silver ink for the back electrical contact, a layer of phosphors to change the color of light emitted by the LEDs (from blue to various shades of white), and an insulating layer to prevent short circuits between the front and back. The front electrical contact, which needs to be transparent to let the light out, is made using an ink that contains invisibly small metal wires."