A Comparative Study on a White Organic Light-Emitting Diode Using a Newly Synthesized Nitro-DPVT as the Blue-Emitting Material and as a Host Material for Orange Emission

다국어 초록 (Multilingual Abstract)

A stacked white organic light-emitting diode with two types of blue/orange-emitting-layer structures was created using a newly synthesized blue-emitting material nitro-DPVT, an existing material NPB, and a fluorescent dye of Rubrene. The first structure consisted of glass/ ITO/NPB(200
°A)/NPB:Rubrene(100 °A)/BCP(70 °A)/Alq3(150 °A)/Al(600 °A). To evaluate its properties, the doping concentrations of Rubrene were set at 0.5 %, 0.75 %, and 1.0 % by weight. When the doping
concentration of Rubrene was 0.5 % by weight, the CIE coordinates were (0.3218, 0.3385) at an applied voltage of 15 V. The turn-on voltage was 1 V, the light-emitting turn-on voltage was 3 V, and the external quantum efficiency was over 0.25 %. The other structure was composed of
glass/ITO/NPB(200 °A)/nitro-DPVT(100 °A)/nitro-DPVT:Rubrene (100 °A)/BCP (70 °A)/Alq3(150 °A)/Al(600 °A). When the doping concentrations of Rubrene were 0.5 %, 0.8 %, and 1.3 % by weight, a white emission with CIE coordinates of (0.3259, 0.3395) was obtained for a 1.3 % Rubrene doping
concentration at an applied voltage of 18 V. Its turn-on voltage was 4 V, and its light-emitting turn-on voltage was 4.5 V. The luminance under a current density of 20 mA/cm2 was 876 cd/m2, the luminance efficiency was 4.38 cd/A, and the maximum external quantum efficiency was over
0.472 % at an applied voltage of 19.5 V."