We investigated chemical and electronic structures of copper phthalocyanine (CuPc) for the electron-injection layer between indium tin oxide (ITO) and emission layers in transparent organic light-emitting devices (TOLEDs). Metallic Cu or dicopper oxide (Cu2O) is formed at the ITO/CuPc interface as a damaged layer during the sputtering deposition of ITO and plays a significant role in efficient electron injection from ITO to the emission layer. Sophisticated photoemission experiments revealed that the cause of the formation of the damaged layer is due to the exposure of CuPc to the oxygen plasma, while no significant damage is introduced by argon plasma and reaction with indium and tin atoms. To achieve efficient TOLEDs, the control of the oxygen plasma is essential.
No takes yet. Share an insight, caveat, or question.
Isomura et al. (2001) studied this question.