Carbon nanotube conductance model in parabolic band structure

Ahmadi, Mohammad Taghi; Johari, Zaharah; Amin, N. Aziziah; Mousavi, Seyed Mahdi; Ismail, Razali

doi:10.1109/smelec.2010.5549582

Cited by 17 publications

(18 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The minimum conductance can be observed in charge neutrality point indicating higher resistance around this point. The comparison of the proposed model with other experimental and theoretical studies indicates a good agreement between the presented model in this work with previous studies [47,48]. Furthermore, according to the graph, the results of both modeling works are very close to the experimental work with negligible differences.…”

Section: Conductance Model By Considering Gas Adsorption Effectsupporting

confidence: 86%

An Analytical Conductance Model for Gas Detection Based on a Zigzag Carbon Nanotube Sensor

Hosseingholipourasl

Ariffin

Ahmadi

et al. 2020

Sensors

Self Cite

View full text Add to dashboard Cite

Recent advances in nanotechnology have revealed the superiority of nanocarbon species such as carbon nanotubes over other conventional materials for gas sensing applications. In this work, analytical modeling of the semiconducting zigzag carbon nanotube field-effect transistor (ZCNT-FET) based sensor for the detection of gas molecules is demonstrated. We propose new analytical models to strongly simulate and investigate the physical and electrical behavior of the ZCNT sensor in the presence of various gas molecules (CO2, H2O, and CH4). Therefore, we start with the modeling of the energy band structure by acquiring the new energy dispersion relation for the ZCNT and introducing the gas adsorption effects to the band structure model. Then, the electrical conductance of the ZCNT is modeled and formulated while the gas adsorption effect is considered in the conductance model. The band structure analysis indicates that, the semiconducting ZCNT experiences band gap variation after the adsorption of the gases. Furthermore, the bandgap variation influences the conductance of the ZCNT and the results exhibit increments of the ZCNT conductance in the presence of target gases while the minimum conductance shifted upward around the neutrality point. Besides, the I-V characteristics of the sensor are extracted from the conductance model and its variations after adsorption of different gas molecules are monitored and investigated. To verify the accuracy of the proposed models, the conductance model is compared with previous experimental and modeling data and a good consensus is observed. It can be concluded that the proposed analytical models can successfully be applied to predict sensor behavior against different gas molecules.

show abstract

Section: Conductance Model By Considering Gas Adsorption Effectsupporting

confidence: 86%

An Analytical Conductance Model for Gas Detection Based on a Zigzag Carbon Nanotube Sensor

Hosseingholipourasl

Ariffin

Ahmadi

et al. 2020

Sensors

Self Cite

View full text Add to dashboard Cite

show abstract

“…In other word, mode density M ( E ) increases with energy [37]. Taking into account the spin degeneracy, the number of conduction channels can be defined as:

M (E) = 2 \frac{Δ E}{Δ k . L} = \frac{3 a_{c - c} t}{L} {(\frac{4 E}{3 a_{c - c} t} - \frac{8}{9 d^{2}})}^{1 / 2}

where L denotes the channel length.…”

Section: Proposed Modelmentioning

confidence: 99%

“…This is due to the fact that the expression

\frac{d f}{d E}

is noticeable only near the Fermi energy [12]. Considering the Fermi–Dirac distribution function, conductance can be obtained as [37,40]:

G = \frac{2 q^{2}}{h} \frac{3 a_{c - c} t}{L} {(\frac{4}{3 a_{c - c} t})}^{1 / 2} {\int_{- \infty}^{+ \infty} (E - \frac{3 a_{c - c} t}{3 d^{2}})}^{\frac{1}{2}} d (- \frac{1}{1 + e^{(E - E_{F}) / K_{B} T}})

…”

Section: Proposed Modelmentioning

confidence: 99%

“…Changing the integral boundaries as below, Equation (5) can be rewritten as [37]:

G = \frac{4 q^{2}}{h L} {(3 a_{c - c} t π k_{B} T)}^{\frac{1}{2}} [\int_{0}^{+ \infty} \frac{x^{- 1 / 2}}{(\frac{1}{1 + e^{x - η}})} d x + \int_{0}^{+ \infty} \frac{x^{- 1 / 2}}{(\frac{1}{1 + e^{x + η}})} d x]

where x = ( E − E g )/ k B T and the normalized Fermi energy is given by η = ( E F − E g )/ k B T . This equation can be numerically solved by incorporating the partial integration method.…”

Section: Proposed Modelmentioning

confidence: 99%

“…As a result, the Fermi-Dirac integral can be estimated by Maxwell-Boltzmann distribution factor, ℑ ( η )( E ) = exp ( η ).On the other hand, in the degenerate state, the concentration of electrons in the conduction band goes beyond the density of state, and the Fermi energy which lies within the conduction band and Fermi-Dirac function can be approximated as ℑ ( η )( E ) = 1. Therefore, the general model for the conductance of carbon nanotube-based gas sensors can be derived similar to that of silicon obtained by Gunlycke [37,43]:

G = \frac{4 q^{2}}{h L} {(3 a_{c - c} t π k_{B} T)}^{\frac{1}{2}} [ξ_{\frac{- 1}{2}} (η) + ξ_{\frac{- 1}{2}} (- η)]

…”

Section: Proposed Modelmentioning

confidence: 99%

See 2 more Smart Citations

Analytical Calculation of Sensing Parameters on Carbon Nanotube Based Gas Sensors

Akbari

Buntat

Ahmad

et al. 2014

Sensors

View full text Add to dashboard Cite

Carbon Nanotubes (CNTs) are generally nano-scale tubes comprising a network of carbon atoms in a cylindrical setting that compared with silicon counterparts present outstanding characteristics such as high mechanical strength, high sensing capability and large surface-to-volume ratio. These characteristics, in addition to the fact that CNTs experience changes in their electrical conductance when exposed to different gases, make them appropriate candidates for use in sensing/measuring applications such as gas detection devices. In this research, a model for a Field Effect Transistor (FET)-based structure has been developed as a platform for a gas detection sensor in which the CNT conductance change resulting from the chemical reaction between NH 3 and CNT has been employed to model the sensing mechanism with proposed sensing parameters. The research implements the same FET-based structure as in the work of Peng et al. on nanotube-based NH 3 gas OPEN ACCESSSensors 2014, 14 5503 detection. With respect to this conductance change, the I-V characteristic of the CNT is investigated. Finally, a comparative study shows satisfactory agreement between the proposed model and the experimental data from the mentioned research.

show abstract

Graphene and Carbon Nanotubes

Ouisse¹

2008

Electron Transport in Nanostructures and Mesoscopic Devices

View full text Add to dashboard Cite

show abstract

Carbon nanotube conductance model in parabolic band structure

Cited by 17 publications

References 14 publications

An Analytical Conductance Model for Gas Detection Based on a Zigzag Carbon Nanotube Sensor

An Analytical Conductance Model for Gas Detection Based on a Zigzag Carbon Nanotube Sensor

Analytical Calculation of Sensing Parameters on Carbon Nanotube Based Gas Sensors

Graphene and Carbon Nanotubes

Contact Info

Product

Resources

About