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Publication Citation: Photoconductive lifetimes of carbon nanotubes films

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Author(s): Katie Hurst; Richard K. Ahrenkiel; Steve W. Johnston; Anne Dillon; Lara Roberson; John H. Lehman;
Title: Photoconductive lifetimes of carbon nanotubes films
Published: November 29, 2007
Abstract: The photoconductive recombination lifetimes of carbon nanotube (CNT) thin films as a function of wavelength are measured by resonant-coupled photoconductive decay (RCPCD) method (1). The carrier recombination lifetime is a fundamental property of carbon nanotubes which is typically determined by contact-based techniques or spectroscopic methods. The RCPCD measurement is based on a pump-probe technique in which an optical pump and a low frequency microwave probe are employed and is well suited to characterization of bulk and extrinsic material properties. Our results demonstrate the role of purification and the effect of the interaction of nanotubes and polymers in thin films of multi-walled carbon nanotube and single-walled carbon nanotubes. Possible mechanisms describing the interaction of photoexcited carriers in the nanotube polymer composites will be discussed. Finally, we report the wavelength dependence of photoconductive lifetimes. Raman spectroscopy and UV-VIS absorption measurements provide further identification and characterization of nanotube samples to enable correlation of nanotube properties with the efficiency of charge transport. (1) R.K. Ahrenkiel, S.W. Johnston Mater. Sci. Eng. B 102 (2003) 161
Citation: Materials Research Society (MRS)
Keywords: carbon nanotubes;photoconductivity
Research Areas: Optoelectronics