光发射作为分子结合中的能量损失的探测
Oleksii Ivashenko1, Adam Johan Bergren2, Richard L McCreery1,2
1Department of Chemistry, University of Alberta , 11421 Saskatchewan Dr., Edmonton, Alberta T6G 2M9, Canada.
Journal of the American Chemical Society
|January 9, 2016
概括
从分子连接处发出的可见光显示能量损失在较厚的膜中,表明电子跳转运输. 这与薄膜形成鲜明对比, 揭示了分子电子中的电荷传输机制.
科学领域:
- 分子电子
- 有机半导体
- 固态物理
背景情况:
- 从分子结点发出的可见光可以了解电荷传输.
- 之前的研究将Al/AlOx/Au连接中的光辐射归因于热载体放松.
- 了解分子层中的运输机制对于设备应用至关重要.
研究的目的:
- 调查不同芳香分子层厚度的分子结合的可见光辐射.
- 将光发射特性与电流电压行为相关联.
- 阐明分子薄膜中的电荷传输机制 (例如连贯道与电子跳跃).
主要方法:
- 在碳接触之间制造具有5-19纳米厚的芳香分子层的分子连接.
- 测量电流-电压特征和可见光辐射谱.
- 与Al/AlOx/Au道交叉点的分子交叉点排放的比较
主要成果:
- 观察到的可见光发射与分子连接处的电流电压行为相关.
- 细分子连接 (<5 nm) 呈现出与连贯道相一致的辐射 (最大光子能量 = 应用偏差).
- 较厚的分子连接显示能量损失 (发射光子能量<应用偏差),取决于分子结构和厚度. 酸连接显示线性能量损失 (0.31 eV/nm).
结论:
- 较厚的薄膜中的能量损失排除了连贯的道化,并表明"损耗"运输.
- 从弹性运输转向损耗运输证实了电子跳跃机制的参与.
- 这项研究提供了一种方法来区分分子结点中的不同电子跳转运输模型.
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