中文摘要：

在室温下测量了红荧烯掺杂有机薄膜光致发光的磁场效应．磁场效应的线型可以归结为外加磁场对掺杂的红荧烯分子间发生单重态激子裂变过程的调控作用．实验发现，光致发光磁场效应的幅度与红荧烯分子间的平均间距之间展现出非线性的对应关系．这种现象说明，当改变掺杂分子间的间距时，掺杂分子间的耦合强度变化可以对激子裂变过程的强度产生重要的影响．在理论上，磁效应幅度与分子间距之间的非线性关系可以采用朗道一齐纳的非绝热跃迂理论进行解释．而实验上，研究分子间耦合强度改变时激子裂变过程的变化，是研究激子裂变过程微观动力学的一种重要方法．本研究工作表明，对于利用单重态激子裂变敏化的有机光伏器件，分子间的耦合强度是一个需要考虑的重要因素．

英文摘要：

In this work, the magnetic field effect of photoluminescence （MPL） from rubrene-doped organic films was recorded at room temperature. The measured line shapes were attributed to the field modulation on the rate constant of singlet exciton fission which occurred between the doped rubrene molecules. It was found that the amplitude of MPL exhibited a non-linear dependence on the averaged intermolecular distance. Such an observation implies that the intermolecular coupling （IMC） which is tuned by changing the intermolecular distance is able to significantly affect the intensity of fission process. Theoretically, the non-linear dependence of MPL as a function of intermolecular distance can be explained by using the Landau-Zener theory for non-adiabatic transition. Experimentally, investigating the variation of singlet fission with different IMC could be an important means to study the microscopic dynamics of fission process. Our work reveals that the importance of IMC should be considered for the design of an efficient singlet fission sensitized organic photovoltaic device.