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为了研究三重态激子与电荷作用(triplet-charge interaction,TCI)产生磁电导(magneto-conductance,MC)的原因,分别用Al,Li F/Al和Ca等不同功函数的金属作为阴极制作了一系列红荧烯(rubrene)型有机发光器件.在室温下Al电极器件中出现了随磁场增加单调下降的负MC.器件的电流-电压特征曲线表明,Al电极器件中空穴为多余载流子,电子注入困难易形成陷阱电荷.利用rubrene中单重态激子(singlet,S)和三重态激子(triplet,T)的能量共振改变S激子裂变(STT)和T激子聚变(TTA)来调控T激子的比率,并通过更换阴极来改变电子注入势垒高度从而调控电荷(charge,C)的浓度,最终实现对TCI的调控.调控结果表明,Al电极器件中负的MC不应该是T激子与多余空穴通过解离或者散射通道的TCI引起的,而是T与陷阱中的束缚电子通过TCI的去陷阱(T+C_t→S_0+C)通道淬灭导致的.另外,载流子注入较为平衡的Li F/Al和Ca电极器件的MC比Al电极器件的小1个量级,且随磁场的增加先减小后增大,这并非是因为平衡注入器件内的TCI弱,而是由于器件内rubrene功能层中的陷阱容易被电子占满,TCI去陷阱淬灭通道和陷阱捕获淬灭通道对电流的影响变低.因此,载流子陷阱在TCI的磁效应中具有重要地位,使有机功能层中的陷阱尽量多且不易被载流子占满是利用TCI磁效应的重要方向.
In order to study the causes of the magneto-conductance (MC) generated by triplet-charge interaction (TCI), a metal with different work function such as Al, Li F / Al and Ca A series of rubrene organic light-emitting devices showed a negative MC with a monotonous decrease in magnetic field at room temperature. The current-voltage characteristic curve of the device shows that the holes in the Al-electrode device are excess carriers , Trapped charges are easily formed due to the difficulty of electron injection, and the energy resonance of singlet (S) and triplet (T) in rubrene changes S-stomatal fission (STT) and T-exciton fusion ) To control the ratio of T exciton, and by changing the cathode to change the electron injection barrier height in order to regulate the concentration of charge (C), and finally achieve the regulation of TCI.Control results show that the negative MC device in the negative It should be that the T excitons and excess holes are caused by the TCI of the dissociation or scattering channels, but that the trapped electrons in T and traps are quenched by the TCI traps (T + C_t → S_0 + C) channels. , Carriers injected into MCs that are more balanced Li F / Al and Ca electrode devices This is not because the TCI in the balanced injection device is weak, but because the trap in the rubrene functional layer in the device is easily occupied by electrons Full, TCI to trap quenching channel and trap capture quenching channel on the impact of current becomes low.Therefore, the carrier trap in the magnetic effect of TCI has an important position, so that the organic functional layer of the trap as much as not easily loaded Totals are an important aspect of using the TCI magnetic effect.