Highly efficient red-emission polymer phosphorescent light-emitting diodes based on two novel tris(1-phenylisoquinolinato-C2,N)iridium(III) derivatives

Tris(2-phenylpyridine) iridium (Ir(ppy)3) derivatives are used to fabricate highly efficient red-emission phosphorescent polymer LEDs. The continuous tuning of the electron current to balance the hole current perfectly, by changing the thickness of the electron-injection layer, is demonstrated. Peak efficiencies of 16.9 cd A(-1) and 17.6 lm W-1 are achieved for red emission (see figure).