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介绍了近年来有关磁自旋耦合作用对有机电致发光器件性能影响的研究进展,包括有机磁阻效应、电致发光效应、光电导效应、量子效率效应等。其中,磁场作用下的有机磁阻可达到10%,理论上最大值为-50%;自旋极化注入的引入使得OLEDs的内量子效率达到32%,并且磁场作用下的电致发光强度也增强了8%左右;磁场作用下,器件的光电导和外量子效率分别增大了6%。以上效应随磁场增加逐渐趋于饱和。对于这些效应产生的理论机制,一般认为是由于三线态-三线态的猝灭、塞曼效应及超精细作用等产生的。三线态-三线态的猝灭形成了激发单线态激子S*,形成滞后的电致发光;而塞曼效应及超精细作用则认为是磁场抑制了单线态向三线态的转化致使发光增强。现在这方面的理论仍在完善过程中。
In recent years, the research progress on the effect of magnetic spin coupling on the performance of organic electroluminescent devices is introduced, including organic magnetoresistive effect, electroluminescence effect, photoconductivity effect and quantum efficiency effect. Among them, the magnetic reluctance of the magnetic field can reach 10%, in theory, the maximum value of -50%; spin polarization injection makes the internal quantum efficiency of OLEDs up to 32%, and the electroluminescence intensity of the magnetic field Enhanced about 8%; under the action of a magnetic field, the photoconductivity and external quantum efficiency of the device are respectively increased by 6%. The above effect gradually becomes saturated as the magnetic field increases. The theoretical mechanism for these effects is generally believed to be due to triplet-triplet quenching, Zeeman effect and hyperfine effects. The quenching of the triplet-triplet state forms the excited singlet exciton S * and forms a delayed electroluminescence. The Zeeman effect and the hyperfine effect suggest that the magnetic field suppresses the conversion of the singlet state to the triplet state, resulting in enhanced luminescence. Now the theory is still in the process of improvement.