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室温下,在红色荧光染料掺杂的有机发光器件ITO/N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl)benzidine(NPB)/tris(8-hydroxyquinolato) aluminum (Alq3):4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran(DCM)/Alq3/LiF/Al中,观察到发光随外磁场的变化(即磁致发光)表现为刚开始的快速增加,在~50mT处达到最大后,随着磁场的进一步增加,又呈现出减弱的特点(即高场效应);而且,器件的掺杂浓度越高、所加偏压越大,该高场减弱就越明显.但在另一类绿色荧光染料5,12-dihydro-5,12-dimethylquino[2,3-b]acridine-7,14-dione(DMQA)的掺杂器件中,磁致发光的高场部分则是在~50mT后增加变缓并逐渐趋于饱和.分析结果表明,Frster能量转移过程占主导发射的DMQA掺杂器件,不利于染料分子上三重态激子的形成,从而,通过三重态激子对(triplet pairs)湮灭产生单重态激子(triplet-triplet annihilation,TTA)的过程不易发生;但在载流子陷阱效应参与发射的DCM掺杂器件中,室温下在染料分子上就可以形成寿命较长的三重态激子,增加了发生TTA过程的几率.因此,基于掺杂器件中两种不同的发射机制,外加磁场对有机发光中三重态激子对(T…T)的演化表现出了不同的调控作用.
In the red fluorescent dye-doped organic light-emitting device ITO / N, N’-bis (naphthalen-1-y) -N, N’-bis (phenyl) benzidine (NPB) / tris (8-hydroxyquinolato) aluminum (Alq3): 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) / Alq3 / LiF / Al, the change of luminescence with external magnetic field After reaching the maximum at ~ 50mT, it shows a weakened characteristic (ie, high field effect) as the magnetic field further increases. Moreover, the higher the device doping concentration is, the larger the bias voltage is applied However, in the doping device of another kind of green fluorescent dye 5,12-dihydro-5,12-dimethylquino [2,3-b] acridine-7,14-dione (DMQA) The luminescence of the high-field part is slowed down and gradually becomes saturated after ~ 50mT. The analysis results show that the Frster energy transfer process dominated the emission of DMQA doping device, is not conducive to the triplet state dye excimer Thus, the process of generating triplet-triplet annihilation (TTA) by triplet pairs of annihilation hardly occurs; however, in the case of carrier trap effect And emitting DCM doping devices, longer lifetime triplet excitons can be formed on dye molecules at room temperature, which increases the probability of TTA. Therefore, based on two different emission mechanisms in doped devices, The magnetic field shows different regulation on the evolution of triplet exciton pair (T ... T) in organic light.