First-principles investigation of the asymmetric contact effect on current-voltage characteristics of a molecular device

2008 ◽  
Vol 128 (4) ◽  
pp. 044711 ◽  
Author(s):  
Z. Zhang ◽  
Z. Yang ◽  
J. Yuan ◽  
M. Qiu
Keyword(s):  
First Principles ◽  
Molecular Device ◽  
Contact Effect ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Asymmetric Contact

First-Principles Modeling for Current-Voltage Characteristics of Resistive Random Access Memories

2013 ◽  
Vol 1562 ◽  
Author(s):  
Takehide Miyazaki ◽  
Hisao Nakamura ◽  
Kengo Nishio ◽  
Hisashi Shima ◽  
Hiroyuki Akinaga ◽  
...  
Keyword(s):  
First Principles ◽  
Oxygen Vacancies ◽  
Electrode Materials ◽  
Random Access ◽  
Model Systems ◽  
Electronic Coupling ◽  
Current Ratio ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Non Equilibrium Green’S Function

ABSTRACTWe present results of first-principles non-equilibrium Green’s function calculations for current-voltage (IV) characteristics of the electrode/HfO2/electrode model systems. In order to investigate the effect of the electrode materials on the IV characteristics, we considered two transition metals for electrode, Ta and W, which are both body-centered-cubic elemental metals but have different valence numbers. We simulated the ON state by placing oxygen vacancies in the HfO2 layer while the OFF state was modeled with HfO2 without oxygen vacancies. At the OFF state, no electric current flowed for -1 V up to +1 V, as expected. At the ON state, however, we found that the absolute current for the Ta electrode was twice as large as that for the W electrode. The analysis of the IV characteristics shows that the electronic coupling between Ta and HfO2 is substantially stronger than that between W and HfO2. Our study demonstrates the importance of the matching between electrode and insulator materials to achieve a high ON- to OFF-current ratio in ReRAMs at a low bias.

The switching behaviors induced by torsion angle in a diblock co-oligomer molecule with tailoring graphene nanoribbon electrodes

2018 ◽  
Vol 32 (04) ◽  
pp. 1850036 ◽  
Author(s):  
Aiyun Yang ◽  
Caijuan Xia ◽  
Boqun Zhang ◽  
Jun Wang ◽  
Yaoheng Su ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Torsion Angle ◽  
Density Functional ◽  
Graphene Nanoribbon ◽  
Molecular Device ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Current Voltage ◽  
Current Voltage Characteristics

By applying first-principles method based on density functional theory combined with nonequilibrium Green’s function, we investigate the effect of torsion angle on the electronic transport properties in dipyrimidinyl–diphenyl co-oligomer molecular device with tailoring graphene nanoribbon electrodes. The results show that the torsion angle plays an important role on the electronic transport properties of the molecular device. When the torsion angle rotates from 0[Formula: see text] to 90[Formula: see text], the molecular devices exhibit very different current–voltage characteristics which can realize the on and off states of the molecular switch.

Negative differential resistance in “sulflower”-based molecular junction predicted by first-principles study

2021 ◽  
pp. 2150167
Author(s):  
Ji-Mei Shen ◽  
Jing Liu
Keyword(s):  
First Principles ◽  
Coulomb Blockade ◽  
Negative Differential Resistance ◽  
Local Density ◽  
Differential Resistance ◽  
Differential Conductance ◽  
First Principles Study ◽  
Current Voltage ◽  
Potential Applications ◽  
Current Voltage Characteristics

The electronic transport behavior of a sulflower molecule sandwiched between metal leads by S atom connecting apex Au or Ag atoms was investigated using a first-principles study by current-voltage characteristics, transmission spectrum and local density of states. Negative differential resistance (NDR) effect which originates from Coulomb blockade driven by bias was obtained. We also found that the differential conductance can be modulated by the metal leads with different work functions, which promise the potential applications in molecular devices in the future.

scholarly journals Quantitative Current–Voltage Characteristics in Molecular Junctions from First Principles

Nano Letters ◽  
2012 ◽  
Vol 12 (12) ◽  
pp. 6250-6254 ◽  
Author(s):  
Pierre Darancet ◽  
Jonathan R. Widawsky ◽  
Hyoung Joon Choi ◽  
Latha Venkataraman ◽  
Jeffrey B. Neaton
Keyword(s):  
First Principles ◽  
Molecular Junctions ◽  
Current Voltage ◽  
Current Voltage Characteristics
Sign in / Sign up

Export Citation Format

Share Document