吡唑啉衍生物有机电致发光器件中激基复合物的发射

以两种吡唑啉衍生物为空穴传输材料(HTM)和BBOT为电子传输材料组成双层器件, 获得了相对于组成材料的荧光光谱红移和宽化的电致发光. 双层器件和HTM∶BBOT等摩尔混蒸薄膜的光致发光及电致发光测量表明, 该谱带来自HTM/BBOT界面激基复合物的发射, 根据器件的能级图, 激基复合物的类型为BBOT的激发态BBOT⁽与基态的HTM相互作用的复合物. 用HTM∶BBOT混合发光层增加器件中激基复合物的形成界面, 提高了器件的发射性能.

Exciplex Emissions from Organic Electroluminescent Devices Containing Pyrazoline Derivates

The bilayer organic electroluminescent diodes using two novel pyrazoline derivatives as hole transporting materials (HTM) and BBOT 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene] as electron transporting material have been constructed, in which the electroluminescent spectra were red-shifted and broadened relative to the fluorescent spectra of constituent materials. Formation of exciplexes at the interfaces of the pyrazoline derivatives and BBOT layers were determined by photoluminescence spectral studies on the HTM/BBOT bilayers and HTM∶BBOT mixed evaporated films as well as electroluminescence measurements. The type of exciplexes formed by the interaction between the excited state of BBOT (BBOT⁽) and ground state of the HTM were confirmed in light of the energy level diagram of these bilayer devices. The maximum luminance and efficiency of the HTM∶BBOT mixed emissive layer devices in which the interface of exciplex formation was enlarged, have been improved by about a factor of 2 in comparing with the corresponding bilayer devices.