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

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.

scholarly journals High electronic couplings of single mesitylene molecular junctions

2015 ◽  
Vol 6 ◽  
pp. 2431-2437 ◽  
Author(s):  
Yuki Komoto ◽  
Shintaro Fujii ◽  
Tomoaki Nishino ◽  
Manabu Kiguchi
Keyword(s):  
Charge Transport ◽  
Channel Model ◽  
Single Channel ◽  
Molecular Junctions ◽  
Liquid Environment ◽  
Resonant Tunnelling ◽  
Current Voltage ◽  
Electronic Conductance ◽  
Current Voltage Characteristics ◽  
High Conductance

We report on an experimental analysis of the charge transport properties of single mesitylene (1,3,5-trimethylbenzene) molecular junctions. The electronic conductance and the current–voltage characteristics of mesitylene molecules wired into Au electrodes were measured by a scanning tunnelling microscopy-based break-junction method at room temperature in a liquid environment. We found the molecular junctions exhibited two distinct conductance states with high conductance values of ca. 10−1 G 0 and of more than 10−3 G 0 (G 0 = 2e 2/h) in the electronic conductance measurements. We further performed a statistical analysis of the current–voltage characteristics of the molecular junctions in the two states. Within a single channel resonant tunnelling model, we obtained electronic couplings in the molecular junctions by fitting the current–voltage characteristics to the single channel model. The origin of the high conductance was attributed to experimentally obtained large electronic couplings of the direct π-bonded molecular junctions (ca. 0.15 eV). Based on analysis of the stretch length of the molecular junctions and the large electronic couplings obtained from the I–V analysis, we proposed two structural models, in which (i) mesitylene binds to the Au electrode perpendicular to the charge transport direction and (ii) mesitylene has tilted from the perpendicular orientation.

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 Inelastic Current-Voltage Characteristics of Atomic and Molecular Junctions

Nano Letters ◽  
2005 ◽  
Vol 5 (4) ◽  
pp. 813-813
Author(s):  
Yu-Chang Chen ◽  
Michael Zwolak ◽  
Massimiliano Di Ventra
Keyword(s):  
Molecular Junctions ◽  
Current Voltage ◽  
Current Voltage Characteristics
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