Photophysics and photoelectrochemical properties of nanohybrids consisting of fullerene-encapsulated single-walled carbon nanotubes and poly(3-hexylthiophene)
Photophysics and photoelectrochemical properties of nanohybrids consisting of fullerene-encapsulated single-walled carbon nanotubes and poly(3-hexylthiophene)
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DOI：
10.1039/c0ee00482k
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发表时间：
2011-03-01
影响因子：
32.5
通讯作者：
Imahori, Hiroshi
中科院分区：
文献类型：
--
作者：
Tezuka, Noriyasu;Umeyama, Tomokazu;Imahori, Hiroshi
首次制备了包覆C-60或C-70的单壁碳纳米管与聚(3-己基噻吩基)(P3HT)的纳米杂化材料，并对其光物理和光电化学性能进行了详细的研究。单壁碳纳米管侧壁和P3HT之间强烈的pi-pi相互作用使所谓的富勒烯豆荚成功地溶解到有机溶剂中，就像在空单壁碳纳米管(p-SWNTs)的情况下一样。无论富勒烯的插入与否，SWNT-P3HT杂化材料中P3HT的荧光发射都被单壁碳纳米管完全猝灭。瞬时吸收和荧光上转换技术揭示了纳米杂化材料的激发态动力学，其中主要发生在短寿命的P3HT单重态(类似于0.2ps)与富勒烯豆荚形成激基缔合物，然后在类似于1ps的范围内向基态松弛。包裹C-60和C-70后的光动力学没有明显的差异，这意味着富勒烯几乎不参与激发态事件，因此被包裹的富勒烯不能在富勒烯豆荚和P3HT之间产生电荷分离态。基于Peapod-P3HT纳米杂化的光电化学器件表现出与基于p-SWNT-P3HT的器件几乎相同的入射光电流效率，这与时间分辨光谱的结果很好地一致。因此，本文所获得的结果将对富勒烯豆荚共轭聚合物以及单壁碳纳米管共轭聚合物杂化材料的光物理和光电化学性质有深入的了解，从而为豆荚光电器件的设计提供有价值的信息。
Novel nanohybrids of single-walled carbon nanotubes (SWNTs) encapsulating C-60 or C-70 with poly(3-hexylthiophene) (P3HT) have been prepared and their photophysics and photoelectrochemical properties are studied in detail for the first time. Strong pi-pi interaction between the SWNT sidewalls and P3HT afforded successful dissolution of the so-called fullerene peapods into an organic solvent, as in the case of empty SWNTs (p-SWNTs). Fluorescence emission of P3HT in the SWNT-P3HT hybrids was completely quenched by the SWNTs regardless of the fullerenes insertion. Transient absorption and fluorescence up-conversion techniques revealed the excited state dynamics of the nanohybrids, where exciplex formation from the short-lived P3HT singlet excited state (similar to 0.2 ps) with the fullerene peapods and subsequent relaxation to the ground state within similar to 1 ps occurred dominantly. Significant difference in the photodynamics upon encapsulation of C-60 or C-70 was not detected, implying little participation of the fullerenes in the excited state event and thus the inability of the encapsulated fullerenes to generate the charge-separated state between the fullerene peapods and P3HT. Photoelectrochemical devices based on the peapod-P3HT nanohybrids showed almost the same incident photon-to-current efficiencies as those for the p-SWNT-P3HT-based device, which is in good agreement with the results of the time-resolved spectroscopies. Thus, the results obtained here will give a deep insight into the photophysics and photoelectrochemical properties of fullerene peapod-conjugated polymer as well as SWNT-conjugated polymer hybrids and therefore provide valuable information on the design of peapod-based optoelectronic devices.