Electrical Contact Resistance at the Carbon Nanotube/Pd and Carbon Nanotube/Al Interfaces in End-Contact by First-Principles Calculations

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Feng Gao ◽  
Jianmin Qu ◽  
Matthew Yao

Reported in this paper is a quantum mechanics study on the electronic structure and contact resistance at the interfaces formed when an open-end single-walled carbon nanotube (CNT) is in end-contact with aluminum (Al) and palladium (Pd), respectively. The electronic structures are computed using a density functional theory (DFT), and the transmission coefficient is calculated using a nonequilibrium Green’s function (NEGF) in conjunction with the DFT. The current–voltage relation of the simulating cell is obtained by using the Landauer–Buttiker formula, from which the contact resistance can be determined. Our results show that the electronic structure and electron transport behavior are strongly dependent on the electrode. It is found that the CNT/Pd interface has a weaker bond than the CNT/Al interface. However, the CNT/Pd interface shows a lower electrical contact resistance.

Author(s):  
Feng Gao ◽  
Jianmin Qu ◽  
Matthew Yao

Due to their unique and superior mechanical and electrical properties, carbon nanotubes (CNTs) are a promising candidate as electrical interconnects in nanoscale electronics. A key element in using CNT as electrical interconnects is the full understanding of the mechanical and electrical behavior of the interface between the CNT and copper (Cu) pad. The objective of this paper is to study the electronic structure and the electrical contact resistance at the interface between the open end of a single wall CNT and a Cu pad. To accomplish this, simulation cell consisting of an open-end single wall CNT with each end connected to a Cu electrode was created. The Cu/CNT/Cu system is fully relaxed first before a potential bias is prescribed between the Cu electrodes. The first-principle quantum mechanical density functional and non-equilibrium Green’s function (NEGF) approaches are adopted to compute the transport coefficient, while the current-voltage (I-V) relation is then extracted by invoking the Landauer-Buttiker formalism. The average density of state (DOS) and local density of states (LDOS) are also calculated to obtain the electron energy distribution around Fermi level point. Our simulation results show that electrons are conducted through the Cu/CNT/Cu system. In the low voltage bias regime (0.0∼0.1 V), I-V relationship is found to be linear. At higher voltage (> 2.0 V), the I-V relationship is nonlinear. Our results also show that the electrical contact resistance at the CNT/Cu interface is ∼3.6 kΩ at 0.1 V, and ∼4.8 kΩ at 2.0 V. These results indicate that for open-end CNTs, the contact resistance at the CNT/Cu interface is at least comparable to that of solder/Cu interface.


Author(s):  
Feng Gao ◽  
Jianmin Qu ◽  
Matthew Yao

The carbon nanotube (CNT) is becoming a promising candidate as electrical interconnects in nanoscale electronics. This paper reports the electronic structure and the electrical conducting properties at the interface between an open-end single wall CNT (SWCNT) and various metal electrodes, such as Al, Au, Cu, and Pd. A simulation cell consisting of an SWCNT with each end connected to the metal electrode was constructed. A voltage bias is prescribed between the left- and right-electrodes to compute the electronic conductance. Due to the electronic structure, the electron density and local density of states (LDOS) are calculated to reveal the interaction behavior at the interfaces. The first-principle quantum mechanical density functional and non-equilibrium Green’s function (NEGF) approaches are adopted to compute the transport coefficient. After that, the voltage-current relation is calculated using the Landauer-Buttiker formalism. The results show that electrons are conducted through the electrode/CNT/electrode two-probe system. The contact electronic resistance is calculated by averaging the values in the low voltage bias regime (0.0–0.1 V), in which the voltage–current relationship is found to be linear. And the electrical contact conductance of electrode/CNT/electrode system show the electrode-type dependent, however, the amplitude for different electrodes is of the same order.


2017 ◽  
Vol 19 (33) ◽  
pp. 22344-22354 ◽  
Author(s):  
Sajjad Ali ◽  
Tian Fu Liu ◽  
Zan Lian ◽  
Bo Li ◽  
Dang Sheng Su

The mechanism of CO oxidation by O2 on a single Au atom supported on pristine, mono atom vacancy (m), di atom vacancy (di) and the Stone Wales defect (SW) on single walled carbon nanotube (SWCNT) surface is systematically investigated theoretically using density functional theory.


RSC Advances ◽  
2015 ◽  
Vol 5 (68) ◽  
pp. 55458-55467 ◽  
Author(s):  
Ping Lou

Hybrid structures of a zigzag edge BN nanoribbon/single-walled carbon nanotube, have been studied via standard spin-polarized density functional theory (DFT) calculations as well as ab initio molecular dynamics (MD) simulations.


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