A high efficiency green phosphorescent OLED with simple double emission layer structure

Using a $Ir(ppy)_3$ doped in hole and electron transport host materials, simple three layers green PHOLEDs comprising double emissive layers have been fabricated. A low driving voltage value of 3.3 V to reach a luminance of $1000\;cd/m^2$ and maximum current- and power-efficiency values of 53.9 cd/A and 57.8 lm/W are demonstrated in this simple structure phosphorescent OLED.