Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Fermi Level Dynamics01:12

Fermi Level Dynamics

The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Band Theory02:35

Band Theory

When two or more atoms come together to form a molecule, their atomic orbitals combine and molecular orbitals of distinct energies result. In a solid, there are a large number of atoms, and therefore a large number of atomic orbitals that may be combined into molecular orbitals. These groups of molecular orbitals are so closely placed together to form continuous regions of energies, known as the bands.
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
Energy Bands in Solids01:01

Energy Bands in Solids

Isolated atoms have discrete energy levels that are well described by the Bohr model. And, it quantifies the energy of an electron in a hydrogen atom as En. Higher quantum numbers 'n' yield less negative, closer electron energy levels.
 Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...
Fermi Level01:18

Fermi Level

The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
Mechanisms of Membrane-bending01:15

Mechanisms of Membrane-bending

The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Valence Bond Theory02:42

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Extraction of Soybean and Pea Protein Isolates to Evaluate Therapeutic Potential Against Dexamethasone-Induced Osteoporosis: In Vivo and <i>in Silico</i> Insights.

Food science & nutrition·2026
Same author

Forearm Radiomyography for Character and Writer Identification in Air Writing.

IEEE journal of electromagnetics, RF and microwaves in medicine and biology·2026
Same author

Exploring the Nutraceutical Potential of <i>Achillea millefolium</i> L.: Phytochemical Composition, Biological Activities, and Industrial Applications.

Food science & nutrition·2026
Same author

Hepato-Renal Axis: A Systematic Review of Anthocyanin Protective Mechanisms of Preclinical Evidence.

Molecular nutrition & food research·2026
Same author

Investigating the phytotherapeutic efficacy of <i>Acacia nilotica</i> pod ethanolic extract in modulating lipid profile, oxidative stress and inflammation in diet-induced hypercholesterolemia: <i>in vivo</i> and <i>in silico</i> insights.

Frontiers in pharmacology·2026
Same author

Social challenges and support needs of patients with hemophilia in Pakistan: a qualitative exploratory study.

Expert review of hematology·2026

Related Experiment Video

Updated: May 30, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
13:56

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Field modulation in bilayer graphene band structure.

Hassan Raza1, Edwin C Kan

  • 1School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA.

Journal of Physics. Condensed Matter : an Institute of Physics Journal
|August 6, 2011
PubMed
Summary

External electric fields can tune the band gap of bilayer graphene. Reduced interlayer distance enhances band gap modulation, with distinct direct and indirect band gap behaviors observed below and above 2.5 Å.

More Related Videos

Optimized Fabrication Procedure for High-Quality Graphene-based Moir&#233; Superlattice Devices
11:24

Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices

Published on: July 11, 2025

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
10:36

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Published on: January 21, 2016

Related Experiment Videos

Last Updated: May 30, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
13:56

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Optimized Fabrication Procedure for High-Quality Graphene-based Moir&#233; Superlattice Devices
11:24

Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices

Published on: July 11, 2025

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
10:36

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Published on: January 21, 2016

Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Nanotechnology

Background:

  • Bilayer graphene exhibits tunable electronic properties via external stimuli.
  • Bernal stacked bilayer graphene's band gap can be modulated by electric fields, breaking sublattice symmetry.
  • Strain engineering offers a pathway to modify graphene's electronic structure.

Purpose of the Study:

  • To investigate the influence of interlayer distance and strain on the electric field-induced band gap modulation in Bernal stacked bilayer graphene.
  • To analyze the relationship between interlayer distance and the nature (direct/indirect) and behavior of the band gap under an electric field.
  • To understand the role of stacking distance in determining the electric field response and saturation of the band gap.

Main Methods:

  • Utilizing the extended Hückel theory for electronic structure calculations.
  • Simulating the effects of varying interlayer distances and applied external electric fields.
  • Analyzing the resulting band gap as a function of electric field strength and stacking separation.

Main Results:

  • Reduced interlayer distance leads to increased band gap modulation by the electric field.
  • Above approximately 2.5 Å interlayer distance, a direct band gap is observed, exhibiting a convex relationship with the electric field and saturating at a distance-dependent value.
  • Below approximately 2.5 Å, an indirect band gap emerges, showing a concave trend with a threshold electric field that is also dependent on stacking distance.

Conclusions:

  • Interlayer distance is a critical parameter in controlling the band gap modulation and electronic behavior of bilayer graphene under electric fields.
  • The transition from direct to indirect band gap at ~2.5 Å interlayer distance signifies a fundamental change in electronic response.
  • Strain effects, particularly changes in interlayer distance, offer tunable control over the electronic properties of bilayer graphene for potential device applications.