采用Li_3Nn型掺杂层作为电子注入层的OLED器件研究

Organic Light-emitting Device with Li_3N n-type Doped Electron Injecting Layer

相对于传统的无机半导体材料,有机半导体材料特别是有机电子传输材料的载流子浓度和迁移率较低,从而影响了有机发光器件的亮度、效率等性能.为了提高有机发光器件器件性能必须增强电子注入和传输能力,对有机电子传输材料进行n型电学掺杂能够有效地提高电子的注入和传输能力.本文利用Li3N作为n型掺杂剂,以掺杂层Alq3∶Li3N作为电子注入层,有效地提高了有机发光器件器件的性能,在掺杂浓度为5%,掺杂层厚度为10 nm时器件性能表现为最优.Li3N在空气中稳定,并且在较低的温度和压强下能分解产生Li原子和氮气,避免了采用金属掺杂剂如Li、Cs等材料时易受空气中水分和氧气影响的缺点,有利于工艺处理.

The carrier density mobility in organic electron transporting semiconductor is very low compared with the inorganic semiconductor,which affects the efficiency and luminance of Organic Light-emitting Devices（OLEDs）.To improve the performance of OLED,the electron injecting and transporting ability should be enhanced,and n-type electrically doping can enhance the electron transporting ability of the orangic materials.Li3N was used as n-type dopant and Alq3∶Li3N doped layer was used as the electron injecting layer for OLED.As a result,the performance of OLED were improved.The optimal doping concentration and the thickness were 5% and 10 nm,respectively.Because Li3N is stable in the air and can decomposite to Li atoms and nitrogen at a low temperature and pressure,the disadvantage can be avoided of the effecting of moisture and oxygen to the metal dopant such as Li and Cs.The research result is also helpful to the preserve and doping process.