Conductivity of ZnO nanomaterials measured by terahertz time-domain

Terahertz time-domain spectroscopy was used to measure the optical properties of ZnO nanoparticles (NPs) in the composite samples. The complex conductivity of pure ZnO NPs was extracted by applying Bruggeman effective medium theory. We find that the real part of the complex conductivities increase with the increasing diameter of the ZnO NPs and are governed by a restricted mean free path for NPs. The results demonstrate that carriers become localized with a backscattering behavior in nano-structured ZnO.

[1]  Haim Grebel,et al.  Optical and electronic characteristics of single walled carbon nanotubes and silicon nanoclusters by tetrahertz spectroscopy , 2004 .

[2]  Yang Yu-Ping,et al.  Far-infrared conductivity of CuS nanoparticles measured by terahertz time-domain spectroscopy , 2010 .

[3]  M Bonn,et al.  Local field effects on electron transport in nanostructured TiO2 revealed by terahertz spectroscopy. , 2006, Nano letters.

[4]  J. Garnett,et al.  Colours in Metal Glasses and in Metallic Films. , 1904, Proceedings of the Royal Society of London.

[5]  Matthew C. Beard,et al.  Size-Dependent Photoconductivity in CdSe Nanoparticles as Measured by Time-Resolved Terahertz Spectroscopy , 2002 .

[6]  Abul K. Azad,et al.  Terahertz dielectric properties of high-resistivity single-crystal ZnO , 2006 .

[7]  E. Kane.  Pollmann-Büttner variational method for excitonic polarons , 1978 .

[8]  Huifang Xu,et al.  Complex and oriented ZnO nanostructures , 2003, Nature materials.

[9]  A. Azad,et al.  Optical and dielectric properties of ZnO tetrapod structures at terahertz frequencies , 2006 .

[10]  Charles A Schmuttenmaer,et al.  Conductivity of ZnO nanowires, nanoparticles, and thin films using time-resolved terahertz spectroscopy. , 2006, The journal of physical chemistry. B.

[11]  D. A. G. Bruggeman.  Berechnung verschiedener physikalischer Konstanten von heterogenen Substanzen. I. Dielektrizitätskonstanten und Leitfähigkeiten der Mischkörper aus isotropen Substanzen , 1935 .

[12]  Fujii,et al.  Infrared absorption in SiO2-Ge composite films: Influences of Ge microcrystals on the longitudinal-optical phonons in SiO2. , 1992, Physical review. B, Condensed matter.

[13]  Xu Xie,et al.  Detection of broadband terahertz waves with a laser-induced plasma in gases. , 2006, Physical review letters.

[14]  Paul Mulvaney,et al.  Surface Plasmon Spectroscopy of Nanosized Metal Particles , 1996 .

[15]  M. Dresselhaus,et al.  Infrared absorption in bismuth nanowires resulting from quantum confinement , 2002 .

[16]  M. Naughton,et al.  Aligned Ultralong ZnO Nanobelts and Their Enhanced Field Emission , 2006 .