September 17, 2013…Physicists at the University of Utah claim to have taken a step towards truly white OLEDs with the development of color tunable polymer. They developed a plastic-like organic polymer that can emit a different color of light depending upon what intervals along the polymer chain, platinum atoms are placed. So in theory, the physicists could place the platinum atoms with an interval that produces light with colors along the entire visible spectrum to produce white light.
“These new, platinum-rich polymers hold promise for white organic light-emitting diodes and new kinds of more efficient solar cells,” said University of Utah physicist Z. Valy Vardeny, who led a study of the polymers published online Friday, Sept. 13 in the journal Scientific Reports.
Existing white OLED displays, such as those in recent cell phones, use different organic polymers that emit different colors, which are arranged in pixels of red, green and blue and then are combined to make white light, said Vardeny, a distinguished professor of physics. “This new polymer has all those colors simultaneously, so no need for small pixels and complicated engineering to create them.”
“This polymer emits light in the blue and red spectral range, and can be tuned to cover the whole visible spectrum,” he added. “As such, it can serve as the active [or working] layer in white OLEDs that are predicted to replace regular light bulbs.”
Vardeny says the new polymer also could be used in a new type of solar power cell in which the platinum would help the polymer convert sunlight to electricity more efficiently. And because the platinum-rich polymer would allow physicists to “read” the information stored in electrons’ “spins” or intrinsic angular momentum, the new polymers also have potential uses for computer memory.
“We haven’t yet fabricated an OLED with it,” Vardeny says. “The paper shows we get multiple colors simultaneously from one polymer,” making it possible to develop an OLED in which single pixels emit white light. Vardeny predicts about one year until the design of a “platinum-rich pi-conjugated polymer” that is tuned to emit white light when stimulated by light, and about two years until development of true white organic LEDs that emit light when stimulated by electricity.