Numerical solution of the Dirac equation for an armchair graphene nanoribbon in the presence of a transversally variable potential

Author(s):  
P. Marconcini ◽  
D. Logoteta ◽  
M. Fagotti ◽  
M. Macucci
2014 ◽  
Vol 974 ◽  
pp. 205-209 ◽  
Author(s):  
Endi Suhendi ◽  
Rifky Syariati ◽  
Fatimah A. Noor ◽  
Neny Kurniasih ◽  
Khairurrijal

We have studied tunneling current in a p-n junction based on armchair graphene nanoribbon (AGNR) by using the relativistic Dirac equation and a transfer matrix method (TMM). The electron wave function was derived by solving the relativistic Dirac equation. The TMM, which is a numerical approach, was used to calculate electron transmittance and the tunneling current. The results showed that the tunneling current increases with the bias voltage. On the other hand, the tunneling current increases with the decreases in the electron incidence angle and temperature. Moreover, the increases in the AGNR width and electric field in the p-n junction result in the increase in the tunneling current.


2015 ◽  
Vol 1112 ◽  
pp. 80-84
Author(s):  
Fatimah A. Noor ◽  
Rifky Syariati ◽  
Endi Suhendi ◽  
Mikrajuddin Abdullah ◽  
Khairurrijal

We have developed a model of the tunneling current in n-p-n bipolar transistor based on armchair graphene nanoribbon (AGNR). Airy-wavefunction approach is employed to obtain electron transmittance, and the obtained transmittance is then used to obtain the tunneling current. The tunneling current is calculated for various variables such as base-emitter voltage, base-current voltage, and AGNR width. It is found that the tunneling current increases with increasing the base-emitter voltage or the base-collector voltage. This result is due to the lowered barrier height of the base region caused by the increase in the base-emitter voltage or the base-collector voltage. In addition, the tunneling current density increases with the width for narrow AGNR and, on the other hand, it decreases for wide AGNR. This finding might be due to the contributions of the band gap energy and the electron effective mass of AGNR which are inversely proportional to the AGNR width.


2014 ◽  
Vol 4 (4) ◽  
pp. 259-262
Author(s):  
Rifky Syariati ◽  
◽  
Endi Suhendi ◽  
Fatimah A. Noor ◽  
Mikrajuddin Abdullah ◽  
...  

2021 ◽  
Author(s):  
Madhusudan Mishra ◽  
N R Das ◽  
Narayan Sahoo ◽  
Trinath Sahu

Abstract We study the electron transport in armchair graphene nanoribbon (AGNR) resonant tunneling diode (RTD) using square and V-shaped potential well profiles. We use non-equilibrium Green’s function formalism to analyze the transmission and I-V characteristics. Results show that an enhancement in the peak current (Ip ) can be obtained by reducing the well width (Ww ) or barrier width (Wb ). As Ww decreases, Ip shifts to a higher peak voltage (Vp ), while there is almost no change in Vp with decreasing Wb . It is gratifying to note that there is an enhancement in Ip by about 1.6 times for a V-shaped well over a square well. Furthermore, in the case of a V-shaped well, the negative differential resistance occurs in a shorter voltage range, which may beneficial for ultra-fast switching and high-frequency signal generation. Our work anticipates the suitability of graphene, having better design flexibility, to develop ideally 2D RTDs for use in ultra-dense nano-electronic circuits and systems.


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