摘要
Efficient red organic light-emitting device consisted of a compound fluorescent-phosphor-sensitized emission layer was fabricated. A novel red fluorescent dye, 3-(dicyanomethylene)-5,5-dimethyl-1-(4-dimethylamino-styryl) cyclohexene (DCDDC), and a green phosphorescent dye, fac tris(2-phenylpyridine) iridium [Ir(ppy)3] were codoped into a host material 4,4'-N,N'-dicarbazolebiphe-nyl (CBP). By adjusting the component ratio of doping system, a series of devices with different concentration proportion of Ir(ppy)3:DCDDC were constructed. The results demonstrated that the device with 0.2 wt% DCDDC had a maximum power effi-ciency (ηp) of 2.12 lm/W at a current density of 0.1 mA/cm2, which was about 38% higher than that of conventional fluorescent device. When at a current density of 4 mA/cm2 (100 cd/m2) and 52 mA/cm2 (1000 cd/m2), the ηp percentage was about 160% and 143% higher than that of conventional device, respectively. A stable red light emission at a peak of 615 nm with Commissions Internationale de l'Eclairage coordinates near the region of (0.56, 0.42) in a wide bias range was also obtained. The improved performances were attributed to the efficient multiple-stage energy transfer from the host to the guest and the suppression of loss mechanism.
Efficient red organic light-emitting device consisted of a compound fluorescent-phosphor-sensitized emission layer was fabricated. A novel red fluorescent dye, 3-（dicyanomethylene）-5,5-dimethyl-1-（4-dimethylamino-styryl） cyclohexene （DCDDC）, and a green phosphorescent dye, fac tris（2-phenylpyridine） iridium [Ir（ppy）3] were codoped into a host material 4,4＇-N,N＇-dicarbazotebiphenyl （CBP）. By adjusting the component ratio of doping system, a series of devices with different concentration proportion of Ir（ppy）3：DCDDC were constructed. The results demonstrated that the device with 0.2 wt% DCDDC had a maximum power efficiency （ηp） of 2.12 lm/W at a current density of 0.1 mA/cm^2, which was about 38% higher than that of conventional fluorescent device. When at a current density of 4 mA/cm^2 （100 cd/m^2） and 52 mA/cm^2 （1000 cd/m^2）, the r/p percentage was about 160% and 143% higher than that of conventional device, respectively. A stable red light emission at a peak of 615 nm with Commissions Internationale de l＇Eclalrage coordinates near the region of （0.56, 0.42） in a wide bias range was also obtained. The improved performances were attributed to the efficient multiple-stage energy transfer from the host to the guest and the suppression of loss mechanism.
基金
supported by the National Natural Science Foundation of China (NSFC) (60736005)
Foundation for Innovative Research Groups of the NSFC (60721001)
National High-Tech Research and Development Program of China (2007AA03Z424)
Program for New Century Excellent Talents in University through(NCET-06-0812)
Young Excellence Project of UESTC (060206)
