| 초록 |
Indium tin oxide (ITO) has been commonly used as an anode of organic light emitting diode (OLED) because of relatively high work function, high transmittance, and low resistance. However, interface property between ITO and adjacent organic layer limits hole injection from the anode electrode. In previous paper, we have synthesized 4'-nitrobiphenyl-4-carboxylic acid (NBCA) with biphenyl moiety that makes it possible to improve the interface between ITO and TPD.In this study, we investigated the effect of phenylene ethylene moiety on interface between ITO and adjacent organic layer. We have synthesized 4-[(4-nitrophenyl)ethynyl]benzoic acid (NPBA) and fabricated OLEDs consisting of ITO/NPBA SAM/TPD (600 Å)/Alq3 (600 Å)/Al (600 Å). In combination with the current density-voltage-luminescence (J-V-L) characteristics of these devices, contact angle measurement, and atomic force microscopy have been employed to investigate interface properties of these devices. |
