Warm- to cool-white tunable LED package has high CRI, luminous efficacy

In the quest for ever-better performance of white LEDs for illumination, researchers at Kookmin University (Seoul, South Korea) and PSI Co. (Kyungki-Do, South Korea) have created a series of multipackage LEDs that have luminous efficacies of around 100 lm/W and, at the same time, high Ra color-rendering indices (CRIs) of around 95. What’s most remarkable about the new multipackage LEDs, though, is that these luminous efficacies and CRIs hold while the LEDs are tuned from a warm white (2700 K) color to a cool white (6500 K) color—the entire range of hues needed for most white-light illumination uses.