High performance inkjet printed phosphorescent organic light emitting diodes based on small molecules commonly used in vacuum processes

► Effective inkjet printed organic light emitting diode (OLED) technique is explored. ► Solution process on commonly used hole transporting material (HTM) is demonstrated. ► Triplet energy overlap of HTM and emitting material is the key to the performance. ► Simple inkjet printed OLED provides the high current efficiency of 40 cd/A.