ELECTRIC-FIELD-INDUCED POLARIZATION CURRENT STUDIES IN GUEST-HOST POLYMERS
ELECTRIC-FIELD-INDUCED POLARIZATION CURRENT STUDIES IN GUEST-HOST POLYMERS
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客主聚合物中电场诱导的极化电流研究
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
C. Dirk
中科院分区：
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作者：
K. Zimmerman;F. Ghebremichael;M. Kuzyk;C. Dirk
我们应用极化电流测量研究偶极重取向的非线性生色团，嵌入在聚合物基体中。特别地，我们向掺杂有众所周知的偶极发色团、分散红1或明显中心对称的方酸盐发色团的聚（甲基丙烯酸甲酯）薄膜施加阶跃电压，并测量电流在几个温度下的等温时间行为。通过将电流与电场诱导的二次谐波产生相关联，我们发现在非常早期，极化电流占主导地位，而在稍后的时间，电荷跳跃机制可能占主导地位。对于中心对称方酸盐发色团掺杂剂，我们发现早期电流表明极化衰减，没有相应的二次谐波信号。这表明方酸分子具有垂直于极化率张量主轴的偶极矩，并且与顺式异构体的存在一致。时间-温度-体积
We apply polarization current measurements to study dipole reorientation of nonlinear chromophores that are embedded in a polymer matrix. In particular, we apply a step voltage to a thin film of poly(methyl methacrylate) that is doped with a well‐known dipolar chromophore, Disperse Red 1, or an apparently centrosymmetric squarylium chromophore, and measure the isothermal temporal behavior of the current at several temperatures. By correlating the current with electric‐field‐induced second‐harmonic generation, we find that at very early times, polarization current dominates, while at later times, charge hopping mechanisms probably dominate. For the centrosymmetric squarylium chromophore dopant, we find an early‐time current suggesting polarization decay with no corresponding second‐harmonic signal. This suggests that the squarylium molecule has a dipole moment that is perpendicular to the dominant axis of the polarizability tensor and is consistent with the presence of the cis isomer. A time–temperature–vo...