标题： 关于π共轭聚合物中自旋-1/2光致发光检测磁共振的频率响应和起源的评论 显示英文标题

标题： Comment on Frequency response and origin of the spin-1/2 photolumines-cence-detected magnetic resonance in a pi-conjugated polymer

摘要： 在最近的一篇论文中，Segal 等人[1]试图用一种模型（称为 TPQ）来解释一种π共轭聚合物薄膜中的自旋1/2光致发光检测磁共振（PLDMR）的动力学，这种聚合物是一种可溶性聚（苯基乙烯）的衍生物[MEH-PPV]，其中PLDMR是由于自旋依赖的三重态极化子相互作用，这种相互作用降低了极化子密度并导致单重激发态的猝灭。我们研究了MEH-PPV薄膜在不同温度下微波功率函数的完整PLDMR和光诱导吸收（PA）动力学。我们首先表明，TPQ模型与完整的频率依赖的自旋1/2 PLDMR响应不兼容；其次，它与自旋1 PLDMR的温度依赖性不一致；第三，它预测的三重态激子寿命比实验得到的要短得多；第四，这与自旋1/2 PLDMR和三重态激子PA的温度依赖性相矛盾。相反，另一种模型，即极化子的自旋依赖复合，能够解释全部实验结果，特别是PLDMR动力学。 显示英文摘要

摘要： In a recent paper Segal et al. [1] attempted to explain the dynamics of spin 1/2 photoluminescence detected magnetic resonance (PLDMR) in films of a pi-conjugated polymer, namely a soluble de-rivative of poly(phenylene-vinylene) [MEH-PPV] using a model (dubbed TPQ), in which the PLDMR is due to spin dependent triplet-polaron interactions that reduce the polarons density and consequent quenching of singlet excitons. We studied the full PLDMR and photoinduced ab-sorption (PA) dynamics of MEH-PPV films as a function of microwave power at various tempera-tures. We show, firstly, that the TPQ model is incompatible with the full frequency dependent spin 1/2 PLDMR response; secondly, it is not in agreement with the spin-1 PLDMR temperature dependence; thirdly, it predicts a much shorter triplet exciton lifetime than that obtained experimentally; and fourthly, that is in contradiction with the temperature dependencies of spin 1/2 PLDMR and triplet exciton PA. In contrast, an alternative model, namely the spin dependent re-combination of polarons, is capable of explaining the whole body of experimental results, and in particular the PLDMR dynamics.