| 초록 |
In this work, we investigate energy transfer from exciplex to phosphorescent dopant at interface between emitting layer (EML) and electron transporting layer (ETL) in the organic light emitting diodes (OLEDs). At EML/ETL interface, N,N’-dicarbazolyl-4-4’-biphenyl (CBP), the EML host, and bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), the electron transporting material, form exciplex. We observed that as the concentration of fac tris(2-phenylpyridine) iridium [Ir(ppy)3] near the EML/ETL interface increases, the exciplex emission intensity is decreased and the efficiency of the OLED is increased. This efficiency enhancement caused by increase of energy transfer rate from exciplex to dopant due to decrease of distance between exciplex and dopant. |
