Terahertz time-domain spectroscopy characterization of vertically aligned carbon nanotube films

Katsounaros, Anestis; Mann, M.; Naftaly, Mira; Rajab, Khalid Z.; Hao, Yang; Milne, W. I.

doi:10.1016/j.carbon.2011.09.056

Cited by 13 publications

(11 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Katsounaros et al [224] studied vertically aligned MW CNTs and the results could have been fitted by a Drude term supplemented by a frequency independent conductive contribution. For example, Katsounaros et al [224] studied vertically aligned MW CNTs and the results could have been fitted by a Drude term supplemented by a frequency independent conductive contribution.…”

Section: Thz Response Of Carbon Nanotubesmentioning

confidence: 99%

“…However, in some papers the conductive response of CNT samples did not show a finite-frequency peak and could be described simply by the Drude behavior. For example, Katsounaros et al [224] studied vertically aligned MW CNTs and the results could have been fitted by a Drude term supplemented by a frequency independent conductive contribution. Recently, Gorshunov et al [225] studied nonaligned SW CNTs in a broad range of frequencies and temperatures and reported a metallic like frequency-and temperature-dependent behavior.…”

Section: Thz Response Of Carbon Nanotubesmentioning

confidence: 99%

See 1 more Smart Citation

Terahertz Spectroscopy of Nanomaterials: a Close Look at Charge‐Carrier Transport

Kužel

Němec

2019

Advanced Optical Materials

View full text Add to dashboard Cite

Transport of charges is a fundamental process in many high-tech applications including photovoltaic or optoelectronic devices, but also in more ordinary components such as unsophisticated wires and other circuitry. The development of nanotechnologies resulted in the fabrication of highly complex materials consisting of a large variety of nanosized elements, which inevitably involve a multitude of charge transport processes occurring on various time-and length-scales. Figure 1 summarizes the most common nanoelements with high application potential.For example, the electrodes employed in Grätzel solar cells [1] are composed of percolated networks of a huge number of metal oxide nanoparticles (top-left panel in Figure 1). Colloidal nanocrystals form the basis for thin film electronics and flexible electronic devices. [2] The synthetic approaches control their composition, size and electronic structure (energy levels, density of states within the bands and in the bandgap) and the charge-carrier transport. [2,3] Nanowires and nanotubes made of conventional semiconductors are quasi 1D systems combining Terahertz spectroscopy has been used for almost two decades for investigations of nanomaterials, including nanocrystals, nanoparticles, nanowires, nanotubes or 2D crystals. Its great importance stems from the fact that it is a noncontact method and, owing to its high frequency and broadband character, it is capable of characterizing charge transport properties within individual nano-objects but also among them. In addition, probing of photoinitiated ultrafast charge dynamics is possible thanks to the sub-picosecond time resolution. Despite this unprecedented potential, the interpretation of the measured terahertz conductivity spectra in many materials is still intensively debated. Herein is presented a review of the experiments performed on nanostructures of conventional semiconductors and on carbon nanomaterials (graphene and carbon nanotubes) during the past decade. The state of the art of the theoretical formalism is provided and discussed, including the intrinsic response, as well as the role of inherent heterogeneity and of the experimental conditions.

show abstract

Section: Thz Response Of Carbon Nanotubesmentioning

confidence: 99%

Section: Thz Response Of Carbon Nanotubesmentioning

confidence: 99%

Terahertz Spectroscopy of Nanomaterials: a Close Look at Charge‐Carrier Transport

Kužel

Němec

2019

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…We proceed by first determining the THz properties of the Si/SiO 2 substrate and Al-Fe precursor layer from measurements on additional test samples without the CNT layer. This approach is in contrast to previous reports [5] where the THz transmission was modeled by assuming only a single bulk layer, where the effective conductivity spectra obtained by fitting the experimental data then depended on the sample thickness. This demonstrates the importance of a detailed analysis of the CNT film morphology when attempting to extract the microscopic conductivity properties.…”

Section: Resultsmentioning

confidence: 91%

Role of growth morphology on the terahertz response of vertically aligned carbon nanotubes

Zouaghi

Thomson

Rabia

et al. 2013

2013 38th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

View full text Add to dashboard Cite

show abstract

“…The real dielectric constant is simulated using the general Drude model [23]. Table-1 summarized the fitted parameters.…”

Section: Refractive Index and Permititivy Of Znmgo Nanorodmentioning

confidence: 99%

Growth dependent optical properties of ZnMgO at THz frequencies

Rivera¹,

Mazady²,

Ahi³

et al. 2015

SPIE Proceedings

View full text Add to dashboard Cite

A relatively high Mg mole fraction of 7% is achieved using the cavitation effect under sonication to overcome the low solubility of ZnO-MgO at low temperature. The Mg mole fraction is confirmed by shift in the near band emission of free exciton under photoluminescence spectroscopy at room temperature. The x-ray diffraction pattern has a large peak associated to ZnO (002) from which the c-lattice constant is calculated to be 5.1967Ǻ. The nanorods (NRs) grown via sonochemical are compared to nanowires (NWs) grown using metal organic chemical vapor deposition (MOCVD) and hydrothermal synthesis. Also, the effect of the ZnO film used as seed layer is described and compare to a simple spin coated layer. Terahertz (THz) index of refraction and dielectric constant of wurtzite Zn1-xMgxO NWs with Mg mole fraction of 7% via sonochemical are determined using THz time domain spectroscopy (THz-TDS). The results are compared with ZnO and ZnMgO NWs with 10% Mg mole fraction grown using MOCVD. The successful growth of Zn1-xMgxO with wurtzite structure at low temperature permits realization of the growth of heterostructures, quantum well, nanowires and nanorods on flexible substrates providing lower cost, optical and carrier confinement necessary in advanced light emitting diodes (LEDs), laser diodes (LDs) and high efficiency solar cells.

show abstract

Terahertz time-domain spectroscopy characterization of vertically aligned carbon nanotube films

Cited by 13 publications

References 12 publications

Terahertz Spectroscopy of Nanomaterials: a Close Look at Charge‐Carrier Transport

Terahertz Spectroscopy of Nanomaterials: a Close Look at Charge‐Carrier Transport

Role of growth morphology on the terahertz response of vertically aligned carbon nanotubes

Growth dependent optical properties of ZnMgO at THz frequencies

Contact Info

Product

Resources

About