Ultrafast charge generation in a semiconducting polymer studied with THz emission spectroscopy
Ultrafast charge generation in a semiconducting polymer studied with THz emission spectroscopy
复制标题
使用太赫兹发射光谱研究半导体聚合物中的超快电荷产生
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
M. Bonn
中科院分区：
文献类型：
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作者：
E. Hendry;M. Koeberg;J. Schins;L. Siebbeles;M. Bonn
我们通过用飞秒可见脉冲光激发偏置聚合物后测量辐射太赫兹场来研究半导体聚合物 (MEH-PPV) 中的超快电荷生成。发射波的亚皮秒时间特性反映了超快光电导动力学，并设定了光激发后 200 fs 的电荷生成上限，并揭示了 MEH-PPV 中电荷传输的色散性质。通过对 MEH-PPV 辐射场和特征良好的模型半导体系统 sGaAsd 的辐射场进行比较，可以准确估计聚合物中电荷生成的量子效率，发现该效率小于 1%。这两个观察结果都与半导体聚合物通过热激子解离产生超快电荷一致。
We study the ultrafast charge generation in a semiconducting polymer (MEH-PPV) by measuring the radiated THz field after photoexciting the biased polymer with a femtosecond visible pulse. The subpicosecond temporal characteristics of the emitted wave reflects the ultrafast photoconductivity dynamics and sets an upper limit for charge generation of 200 fs following photoexcitation, and reveals the dispersive nature of charge transport in MEH-PPV. A comparison of the fields radiated from MEH-PPV and the well-characterized model semiconductor system sGaAsd allows for an accurate estimate of the quantum efficiency for charge generation in the polymer, found to be less than 1%. Both observations are consistent with ultrafast charge generation in semiconducting polymers through hot exciton dissociation.