TBPe与MEH-PPV共掺杂的有机电致发光器件的优化研究

Research on Organic Electroluminescence Devices with TBPe Doped MEH-PPV as Luminescent Layer

采用有机小分子TBPe(2,5,8,11-tetratertbutylperylene)以不同比例掺入MEH-PPV(poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene])作为发光层,研究了TBPe不同掺杂比例对器件性能的影响,进而对发光强度进行优化。对于所制备的ITO/PEDOT∶PSS/MEH-PPV/TBPe/Al有机电致发光器件,TBPe的最优蒸镀厚度为0.5 nm,其发光强度相对于标准器件提高了325%。ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Liq/Al有机电致发光器件的最优掺杂比例为MEH-PPV∶TBPe=100∶30(质量比),其发光亮度相比于未掺杂器件提高了44%。在上述器件的基础上增加Alq3层提高电子注入,分别制作了Liq和LiF作为修饰层的ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Alq3/Liq/Al和ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Alq3/LiF/Al多层器件,发光亮度分别达到4 162 cd/m2和4 701 cd/m2。所有器件的电致发光波长均为580 nm,为MEH-PPV的发光,TBPe的掺杂对MEH-PPV的发光起到了增强作用。

The OLED devices with TBPe(2, 5, 8, 11-tetratertbutylperylene) doped (poly [2-methxy-5-(2-ethylhexylxy)-1, 4-phenylenevinylene]) as luminescent layer were fabricated, and the effect of the doping ratio of TBPe to MEH-PPV on the device performance was investigated. The highest efficiency was obtained in the device with the structure of ITO/PEDOT:PSS/MEH-PPV/TBPe(0.5 nm)/Al. The luminous intensity increased by 325% compared with the standard device, the optimized doping ratio of TBPe:MEH-PPV was 30:100 in weight, and the luminous intensity of the device with the optimized TBPe doping ratio increased by 44% compared with no doping device. In order to enhance the electrons injection, the EIL (electron injection layer) of Alq3 and modified layer of Liq and LiF was employed. The brightness of OLED with multi-layer structure and modified layer of Liq and LiF could reach to 4162 cd/m2 and 4701 cd/m2, respectively. The EL wavelength of all the devices is 580 nm that is attributed to MEH-PPV, and the doping of TBPe plays a role of enhancer for the lumininescence of MEH-PPV.