Related Experiment Video
Updated: Mar 26, 2026
11:17
Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor
Published on: February 10, 2014
12.3K
Theoretical Demonstration of the Ionic Barristor
Yifan Nie1, Suklyun Hong2, Robert M Wallace1
1Department of Materials Science and Engineering, The University of Texas at Dallas , Richardson, Texas 75080, United States.
Nano Letters
|February 9, 2016
Summary
This study shows graphene and transition metal dichalcogenides (TMDs) form contacts without Fermi-level pinning. An ionic barristor design leverages this for tunable graphene work functions and dynamic contact switching.
Area of Science:
- Condensed matter physics
- Materials science
- Nanotechnology
Background:
- Fermi-level pinning is a critical factor in semiconductor device performance.
- Graphene and transition metal dichalcogenides (TMDs) are promising 2D materials for electronic applications.
Purpose of the Study:
- To investigate Fermi-level behavior at graphene-TMD interfaces.
- To explore methods for tuning graphene's work function.
- To propose an advanced barristor device design.
Main Methods:
- First-principles simulations were employed to model graphene-TMD interfaces.
- Analysis of the density of states near the Fermi level was performed.
- Ion adsorption was simulated to assess work function modulation.
Main Results:
- Absence of Fermi-level pinning at graphene-TMD interfaces was demonstrated.
- Both ohmic and Schottky contacts were shown to be achievable.
- Graphene's work function was tunable via ion adsorption due to its shallow density of states.
Conclusions:
- Graphene-TMD contacts offer flexibility in device design.
- A novel ionic barristor design enables wide-range work function tuning and dynamic contact switching (p-type ohmic, Schottky, n-type ohmic).
- This work advances the development of tunable 2D electronic devices.
Related Concept Videos
01:21Ohm's Law
12.1K
Many materials exhibit a simple relationship between the values of current, voltage, and resistance, known as Ohm’s law. The current that flows through most substances is directly proportional to the voltage applied to them. The German physicist Georg Simon Ohm (1787–1854) was the first to demonstrate experimentally that the current in a metal wire is directly proportional to the voltage applied. Any material, component, or device that obeys Ohm’s law, where the current...
12.1K
01:19Ohm's Law
2.8K
Resistors are fundamental components in electrical circuits, often manufactured from metallic alloys or carbon compounds. They model a material's ability to resist the flow of electric current, a characteristic that is crucial in controlling and regulating electrical power within a circuit.
This current-resisting behavior of resistors is governed by Ohm's law, which states that the voltage across a resistor is directly proportional to the current flowing through it.
This current-resisting behavior of resistors is governed by Ohm's law, which states that the voltage across a resistor is directly proportional to the current flowing through it.
2.8K
01:28Ionic Association
166
The ionic association is the association of oppositely charged ions in an electrolyte solution to form ion pairs. Bjerrum defined ion pairs as two oppositely charged ions whose electrostatic attraction exceeds the thermal energy of the system, typically expressed as 2kT. Electrostatic attraction depends on ionic charge, separation distance, and the dielectric constant of the medium. Thermal energy, represented by kT, reflects the tendency of ions to move independently due to molecular motion.
166
01:17Theory of Metallic Conduction
1.9K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.9K
01:24Metal-Semiconductor Junctions
1.3K
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
1.3K
01:21DC Battery
1.6K
A conductor needs to be a component of a path that creates a closed loop or full circuit to have a continuous current flowing through it. A current starts to flow if an electric field is created inside an isolated conductor that is not part of a full circuit. The conductor quickly develops a net positive charge at one end and a net negative charge at the other. These charges generate an electric field opposite the direction of the applied electric field, which reduces the current. Eventually,...
1.6K