Energy Alignment of Frontier Orbitals and Suppression of Charge Recombinations in P3HT/SWNT
Energy Alignment of Frontier Orbitals and Suppression of Charge Recombinations in P3HT/SWNT
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DOI：
10.1021/acs.jpcc.5b06876
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发表时间：
2015-11
影响因子：
3.7
通讯作者：
Katsuhiko Nishimra;M. Fujii;R. Jono;K. Yamashita
中科院分区：
文献类型：
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作者：
Katsuhiko Nishimra;M. Fujii;R. Jono;K. Yamashita
聚(3-己基噻吩基)(P3HT)与单壁碳纳米管(SWNTs)的共混物因其优异的电学性质和P3HT螺旋结构所保证的较宽的界面面积而被研究成为有机光伏器件的理想材料。然而，P3HT/SWNT共混物的能量转换效率较低，因此，需要更深入地了解P3HT/SWNT共混物中的电荷分离过程，以实现更高的效率。本文通过研究P3HT在界面和体相的电子结构来解释P3HT/SWNT共混物中的电荷分离过程。我们证明了界面的HOMO能级与体相的HOMO能级之间的差异的存在和根源。这解释了在之前的一次实验中观察到的现象，当时只在含有过量P3HT的混合物中观察到长寿命的载流子。在对电子结构进行研究的过程中，讨论了侧基的作用。
Blends of poly(3-hexylthiophene) (P3HT) and single-walled carbon nanotubes (SWNTs) have been studied as promising materials for organic photovoltaic devices because of the excellent electronic properties of SWNT and a broad interfacial area guaranteed by the helical structure of P3HT at the interface. However, the P3HT/SWNT blends show a low energy conversion efficiency, and thus, a deeper understanding of the charge separation process in the P3HT/SWNT blends is required to achieve improved efficiency. In this paper, the electronic structures of P3HT at the interface and in the bulk phase were studied to elucidate the charge separation process in the P3HT/SWNT blends. We show the existence and origin of the difference between the HOMO levels at the interface and those in the bulk phase. This explains observations in a previous experiment where long-lived charge carriers were only observed in blends containing excess P3HT. In the course of the investigation on the electronic structures, the role of the sid...