Today, two key issues prevent current iridium-based, phosphorescent OLED emitters from gaining a major fraction of the world lighting markets. Firstly, iridium is the fourth rarest naturally-occurring element on the planet, so basing a large-scale, high-volume lighting industry on this resource is risky as well as detrimental to the environment. Secondly, iridium-based blue phosphor devices have short working lifetimes and low energy efficacy that are well-below industry expectations.   Howeve...