Parametric Study of Nanostructure Variations on the Macroscopic Thermal and Electrical Behavior of Neat CNT Thin Film Networks

Author(s):  
Nikhil A. Ashtekar ◽  
David A. Jack

Carbon nanotube thin films are considered by many researchers as a material for the future in many electrical and thermal applications, but a lack of systematic physics-based modeling approaches to quantify the bulk thermal and electrical response due to nanostructure variations makes employing these thin films difficult for commercial applications. In this work we employ the previously presented 3D physics-based computational model for characterizing the bulk thermal and electrical response of a neat carbon nanotube thin film network involving stochastic distributions of length, diameter, chirality, orientation and values of intercontact resistivity obtained from the literature. The model is employed to test the sensitivity of bulk thermal and electrical conductivity on stochastic variations in the nanostructure parameters. We examine the sensitivity of the thin film networks to the experimentally obtained Weibull probability distribution for length and diameter. Additionally, we present a study to quantify the macroscopic conductivity dependence on the nanotube chirality ratio. Through these studies we present an approach that is very generic and can be used for the sensitivity analysis due to variations within the nanostructure.

1997 ◽  
Vol 471 ◽  
Author(s):  
J. Liu ◽  
D. C. Morton ◽  
M. R. Miller ◽  
Y. Li ◽  
E. W. Forsythe ◽  
...  

ABSTRACTZn2SiO4:Mn thin films were deposited and studied as thin film phosphors for flat panel cathodoluminescent displays. Crystallized films with improved electrical conductivity were obtained after conventional and rapid thermal annealings in a N2 environment at 850Xy11100 °C for 0.25 to 60 minutes. A maximum cathodoluminescent efficiency of 1.3 Lm/W was achieved under dc excitation at 1500 volts. The luminescent emission from these thin films was peaked around 525 nm. The decay time of these films was controlled in the range of 2 to 10 ms by varying the deposition and annealing parameters. The fast response time of these thin films overcomes the long decay limitation of the Zn2SiO4:Mn powder phosphor in practical display applications.


2002 ◽  
Vol 730 ◽  
Author(s):  
A. Nuñez Rodriguez ◽  
M.T.S. Nair ◽  
P.K. Nair

AbstractAg2S thin films of 90 nm to 300 nm in thickness were deposited at 70°C on glass substrates immersed in a bath mixture containing silver nitrate, sodium thiosulfate and dimethylthiourea. When the films are heated in nitrogen at temperatures 200°C to 400°C, crystallinity is improved and XRD pattern similar to that of acanthite is observed. These films possess electrical conductivity of 10-3 (ohm cm)-1, are photoconductive and exhibit an optical band gap of 1.36 eV. When Ag2S thin film is deposited over a thin film of Bi2S3, also obtained by chemical bath deposition from bismuth nitrate, triethanolamine and thioacetamide, and heated at 300°C to 400°C in nitrogen, a ternary compound, AgBiS2 is formed. This material has an electrical conductivity of 5x10-5 (ohm cm)-1, is photoconductive and possesses optical band gap 0.95 eV.


1994 ◽  
Vol 369 ◽  
Author(s):  
C. Zhang ◽  
H. Deng ◽  
J. Varon ◽  
B. Abeles ◽  
Y. Yang ◽  
...  

AbstractThin film SrCo0.8Fe0.2O3-δ were made by pulse laser deposition. The electrical conductivity is thermally activated in the temperature 25-500 °C with an activation energy of 0.17-0.19 eV and is temperature independant from 500-800 °C. The optical absorption shows characteristic features which are interpreted qualitatively in terms of a simple band structure diagram.


2007 ◽  
Vol 352 ◽  
pp. 315-318 ◽  
Author(s):  
Akihiko Ito ◽  
Hiroshi Masumoto ◽  
Takashi Goto

Epitaxial BaRuO3 (BRO) and CaRuO3 (CRO) thin films were prepared on (001), (110) and (111) SrTiO3 (STO) single-crystal substrates by laser ablation, and their microstructures and anisotropy of electrical conductivity were investigated. The (205) (104), (110) and (009) oriented BRO thin films, and (001), (110) and (110) oriented CRO thin films were grown epitaxially on (001), (110) and (111) STO substrates with in-plain orientation, respectively. The (009) BRO thin film and (001) CRO thin film has a flat surface result from a good lattice matching to STO substrates. The (205) (104) BRO thin film and (111) CRO thin film exhibited orthogonal- and hexagonal-shaped texture, respectively. The (110) BRO thin film and (110) CRO thin film showed an island growth due to (110) surface feature of cubic perovskite structure. Epitaxial BRO and CRO thin films have a high electrical conductivity with a metallic conduction, the (111) CRO thin films exhibited the highest conductivity of 1.4×105 S·m-1.


1996 ◽  
Vol 453 ◽  
Author(s):  
K. Ozawa ◽  
Y. Sakka ◽  
M. Amano

AbstractLiSbO3thin films have been prepared by the sol-gel process with metal alkoxides using a spin-coating method. The (Oll)-oriented and randomly oriented LiSbO3thin films are obtained by the precursor film crystallizing under an atmosphere of a flowing mixture of water vapor and oxygen, and an air atmosphere, respectively. The two different atmospheres also affect the crystallization temperature of the films. The electrical conductivity of the (Oll)-oriented LiSbO3thin film is approximately one order of magnitude larger than that of the randomly oriented LiSbO3thin film in the temperature range of 380 to 600°C.


Author(s):  
Mithaq M. Mehdy Al-Sultani

In this paper, thin films were made of 10-4 mol/l of Coumarin 4 laser dye dissolved in ethanol, 0.3 g of PVP polymer and 0.04 g of Al2O3 nanoparticles. The electrical properties such as dielectric constant, phase velocity of laser photons inside the film, the film permittivity and permeability, medium impedance, electrical conductivity, skin depth, the electrical response time, magnetic susceptibility and dielectric time have been studied for the prepared thin films at two different Er:YAG laser wavelengths of 1645nm and 1617 nm based on various laser powers in one time and with changed laser exposure periods in the other time. It is observed that the highest laser power consolidates each value of dielectric constant, dielectric time, electrical conductivity, the electrical response time, magnetic susceptibility and the permeability of film because of increasing the abundant energy in films within laser irradiation. The most important conclusion is that the electrical properties were much higher for the prepared thin films irradiated with 1645nm Er: YAG laser wavelength than for those irradiated with 1617nm laser wavelength.


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