蓝绿色磷光OLED的制备及发光性能研究

Preparation and photolumiescence properties of the OLED with greenish blue phosphor

摘要:

以mCP为主体发光材料,蓝绿色磷光染料BGIr1作 为掺杂剂,制备了6种不同BGIr1掺杂量的蓝绿色磷光有机电致发光器件(OLED),研究了不 同掺杂量对蓝绿色磷光OLED器件发光特性的影 响。制得器件的结构为ITO/MoO₃(20nm)/NPB(40nm)/mCP:BGIr1(x%,30nm)/BCP(10nm)/Alq₃(20 nm)/LiF/Al(100nm),其中x%为发光层中磷光染料BGIr1的掺杂量(质量分数)。结果表明,BGIr1掺杂量 为18%时,获得器件的发光性能最佳。18% BGIr 1掺杂器件在488nm和 512nm处获得两个主发射峰,当电 流密度为26.5mA/cm²时,获得最大发光效率为6.2cd/A；在15V驱动电压下,获得最大亮度为6970cd/cm², CIE坐标为(0.17,0.31)。这说明,BGI r1掺杂改善了器件的发光亮度和色纯度,提高了器件的发光效率。

Abstract:

The six greenish-blue phosphorescent organic light emitting devic es (OLEDs) with different greenish-blue light-emitting iridium (BGIr1) doped c ontents using 1,3-bis(9H-carbazal-9-yl)benzene (mCP) as host emitting material,BGIr1as doped material were fab ricated by OLED-V organic multifunctional coating machine.The influence of BGIr1doping content on the luminous performance of gr eenish-blue phosphorescent OLEDs is investigated by Keithley Source 2400,the current-voltage instrument and PR-655photometer.The structure of as-prepared OLED is ITO/MoO₃(20nm)/NPB(40nm)/mCP:BGIr1(x%,30nm)/BCP (10nm)/Alq₃(20nm)/LiF/Al(100nm),where x% is the doping content o f BGIr1in emitting layer.The experimental results show that the luminous performance of the OLED doped with 18% BGIr1is the best.T he two main emitting peaks are gained at 488nm and 512nm,respectively for the OLED doped with 18% BGIr1,a nd the optical luminous efficiency of 6.2cd/A is obtained at current density of 26.5mA/cm².The optical luminance of 6790cd/A is acquired a t driving voltage of 15V,and the CIE coordinates are (0.17,0.31). The results demonstrate that the luminous efficiency,luminance and purity of th e greenish-blue OLED doped with BGIr1are all improved.