共 45 条
Persistent photoconductivity in chemically modified single-wall carbon nanotubes
被引:40
作者:
Khairoutdinov, RF
[1
]
Doubova, LV
Haddon, RC
Saraf, L
机构:
[1] Univ Alaska Fairbanks, Dept Chem & Biochem, Fairbanks, AK 99775 USA
[2] Univ Alaska Fairbanks, Ctr Nanosensor Technol, Fairbanks, AK 99775 USA
[3] Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA
[4] Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA
关键词:
D O I:
10.1021/jp046495m
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
Control of the conductivity of single wall carbon nanotubes (SWNTs) is crucial for the use of carbon nanotubes in molecular electronics. We report a new fundamental characteristic of semiconducting SWNTs: the persistent photoconductivity of chemically modified carbon nanotube films. Illumination of carboxylated semiconducting SWNTs with ultraviolet or visible light causes a persistent decrease in the conductivity of semiconducting films. The photoinduced conductivity persists in the dark with a characteristic half-life of 35 s to 1.2 x 10(3) s at room temperature and an activation energy of 0.35 eV. Infrared illumination restores the conductivity of SWNT films. Ultraviolet and visible light illumination partially refills empty valence band states of chemically modified SWNTs by electron injection from the dopant sites. Photoinduced injection of electrons is accompanied by a decrease of the conductivity of the p-doped SWNT film, because of neutralization of holes by injected electrons. Covalent attachment of ruthenium(II)-tris(2,2'-bipyridine) (Ru(bpy)(3)(2+)) to SWNTs makes carbon nanotubes sensitive to light that has been absorbed by the ruthenium complex and makes the carbon nanotubes persistently photoconductive. The photoconductivity of Ru(bpY)(3)(2+)-SWNT films is presumably due to the injection of holes from *Ru(bpy)(3)(2+) to SWNT with a quantum yield of 0.55. Persistently photoconductive SWNTs have potential uses as nanosized optical switches, photodetectors, electrooptical information storage devices, and chemical sensors.
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页码:19976 / 19981
页数:6
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