A new organic material for white OLED

Abstract

A new organic material Ligand Lhn4 is used to fabricate organic light emitting diodes. There are two peaks in the Photoluminescence (PL) spectrum of Ligand Lhn4; they are 444nm and 482nm. Organic light emitting diode with Al/LiF(0.5nm)/Ligand Lhn4(50nm)/NPB(50nm)/ITO structure was grown by evaporation. The electroluminescence (EL) spectrum shows there is one peak wavelength for OLED located at 486nm, The full width of half maximum (FWHM) is about 112nm, it mean the material Ligand Lhn4 is quite fair for fabrication of white light OLED. The OLED start emit a white near to blue color light at 2V voltage, and the color have no change as the voltage increasing. The I-V and Brightness vs. Voltage curves were measured at air. The maximum brightness is 300cd/m2 at voltage of 15V. A doped device Al/LiF/BePP2:Ligand Lhn4(10%)/NPB/ITO is fabricated to improve the brightness and efficiency of OLED based on Ligand Lhn4.