Wagon-wheel pasta-shaped LED lights could improve smartphone and television screens.
One restriction when developing LED light bulbs is that the light is polarized in one direction which causes a great deal of light to get stuck within the "light-emitting" diode. By using an organic molecule that is the shaped of wagon-wheel pasta instead of spaghetti researchers found a way to release the light, a University of Utah press release reported.
The rotelle-shaped molecule is known as a "pi-conjugated spoked-wheel macrocycle," they allow light to be emitted in all directions. Many of the OLEDS and LED in today's smartphones use spaghetti-shaped polymers ("chains of repeating molecular units"), which can only release polarized light.
"Conjugated [spaghetti shaped] polymers are a terrible mess. They now make only mediocre OLEDs, although people like to claim the opposite," University of Utah physicist John Lupton, lead author of the study, said.
The spaghetti-shape of the polymers only allows light-waves to oscillate in one direction. They cause about 80 percent of the light to be wasted; this new method could lower it to 50 percent.
"This work shows it is possible to scramble the polarization of light from OLEDs and thereby build displays where light doesn't get trapped inside the OLED. We made a molecule that is perfectly symmetrical, and that makes the light it generates perfectly random. It can generate light more efficiently because it is scrambling the polarization. That holds promise for future OLEDs that would use less electricity and thus increase battery life for phones, and for OLED light bulbs that are more efficient and cheaper to operate," he said.
"OLEDs in smart phones have caught on because they are somewhat more efficient than conventional liquid-crystal displays like those used in the iPhone. That means longer battery life. Samsung has already demonstrated flexible, full-color OLED displays for future roll-up smart phones," Lupton said. He believes the new OLEDS could allow the devices to produce light more efficiently.
The pasta-shaped molecules also have the ability to "catch" other molecules, which could make them helpful in biological sensors, which are used in solar cells and switches.
