In this work the magnetic field effects (MFE) on the photoluminescence of MEH-PPV film and nanoparticles were obtained using the MFE technique with continuous-wave photoexcitation. The analysis of the MFE dependence for the MEH-PPV film gave a HWHM (half-width at half maximum) ∼ 65 mT and a total MFE value about 102.8% at 200 mT whereas the MFE dependence of the MEH-PPV nanoparticles showed significant broadening, with their HWHM ∼ 280 mT and a total MFE value of 99% at 550 mT. By a simple theoretical model based on rate equations, the mechanism of the negative magnetic field effect was explained. The observed negative effect was the result of the dominant singlet exciton formation rate in the MEH-PPV nanoparticles. For explaining this negative effect the enhanced triplet-triplet annihilation due to confinement of triplet excitons in the nanoparticles and singlet molecular oxygen-triplet exciton annihilation were proposed.

在这项工作中，使用具有连续波光激发的MFE技术获得了对MEH-PPV膜和纳米颗粒的光致发光的磁场效应（MFE）。对MEH-PPV膜的MFE依赖性进行分析得出HWHM（半峰半宽）约为65 mT，在200 mT时的总MFE值约为102.8％，而MEH-PPV纳米颗粒的MFE依赖性显示出明显的展宽，其HWHM约为280 mT，在550 mT时的总MFE值为99％。通过基于速率方程的简单理论模型，解释了负磁场效应的机理。观察到的负面影响是MEH-PPV纳米粒子中显性单线态激子形成速率的结果。