| 초록 |
Aluminum metal has been known of a relatively low workfunction and good opto-electrical properties. Thus, We expected to enhancement of EL(electroluminescence) efficiency by inserting a very thin metal layer between emitting layer and electron transporting layer. In this paper, The Organic Light Emitting Devices(OLEDs) were fabricated and mesured the optical and electronical characteristics of the devices. The structure of devices was ITO/TPD(50nm)/Alq3(80nm)/Al(0-0.5nm)/PBD(30nm)/LiF(0.5 nm/Al(100nm) by means of thermal evaporation under the pressure of 2Χ10-6torr. The strong peak of EL(Electroluminescence) spectrum showed at 520nm without relation to the difference of thickness and comfirmed by CIE`s coordinates at x=0.3431 and y=0.5253. But, current density vs. voltage and luminescence showed enhancement of emission efficiency for the OLEDs inserted a metal layer. Consequently, it is inferred that the enhancement of EL efficiency from a role of a hole blocking and electron transporting Aluminum layer. |
