USC Researchers See Copper as Iridium Alternative for Smartphone OLED Displays

Copper could be used for more than just casing or circuit board material in future smartphones. Researchers at the University of Southern California, funded by Universal Display, found a way to replace iridium, a rare element, in OLED screens, with cheaper copper, said a Friday Science article. “The current technology that is in every Samsung Galaxy phone, high-end Apple iPhone and LG TV relies on iridium compounds for the colors and light on OLED screens,” said Mark Thompson, chemist at USC, in a Friday news release. Iridium, found primarily in South Africa and parts of Asia, is used for its efficient light emission, but researchers have been looking for an alternative more abundant source, Thompson said. Previous attempts failed because copper complexes used weaker structures, and molecules were “unstable” with shorter life cycles than the iridium compounds. Researchers’ new copper complex is a more-rigid molecular complex, he said. The new compound’s rate of light emission also matches iridium’s, so the energy is converted efficiently into light and color, which could also improve blue light performance in OLEDs, described by researchers as a “bane” of OLED technology due to the short lifetime of blue emissive OLEDs. Rasha Hamze, the study’s lead author, said achieving efficient blue emission out of copper compounds “opens up entirely new possibilities for tackling the problem of short lifetimes.” The USC team submitted a patent application; next, it will test its ability to create more energy-efficient lighting, Thompson said.