Related Experiment Video
Updated: Aug 28, 2025
07:12
A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics
Published on: August 28, 2018
9.8K
Evolution of inter-layer coupling in artificially stacked bilayer MoS2
Suman Sarkar1, H L Pradeepa1, Goutham Nayak2
1Department of Physics, Indian Institute of Science Bangalore 560012 India aveek@iisc.ac.in.
Nanoscale Advances
|September 22, 2022
Summary
Ultra-clean interfaces are crucial for band hybridization in van der Waals heterostructures (vdWh). Controlling inter-layer spacing allows engineering desired optical properties in these atomically-thin materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Van der Waals heterostructures (vdWh) offer tunable electronic and optical properties.
- Interfacial quality significantly impacts the behavior of layered materials.
- Understanding inter-layer coupling is key to controlling vdWh properties.
Purpose of the Study:
- To experimentally investigate the role of interface cleanliness in band hybridization in atomically-thin vdWh.
- To explore the effect of interfacial separation and adsorbates on vdWh optical properties.
- To establish methods for engineering vdWh with specific optical characteristics.
Main Methods:
- Experimental study of photoluminescence emission and Raman spectra.
- Fabrication and characterization of ultra-thin vdWh with varying interfacial quality.
- Analysis of vibrational Raman-active modes and photoluminescence spectra.
Main Results:
- Band hybridization in vdWh requires ultra-clean interfaces.
- Novel vibrational Raman-active modes emerge in clean vdWh, distinct from constituent layers.
- Photoluminescence spectra show significant modifications, with peaks correlating to inter-layer coupling strength.
- Controlled photoluminescence enabled observation of indirect-band peaks.
Conclusions:
- Atomically-clean interfaces are essential for achieving band hybridization in vdWh.
- Inter-layer coupling strength, controllable via inter-layer spacing, dictates optical properties.
- It is possible to engineer the optical properties of atomically-thin vdWh by managing inter-layer coupling.
More Related Videos
04:56Residue-Free Fabrication of van der Waals Heterostructures of Two-Dimensional Materials
Published on: July 18, 2025
223
08:50Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication
Published on: November 28, 2017
9.3K
Related Concept Videos
01:27¹H NMR: Long-Range Coupling
1.9K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.9K
01:24Metal-Semiconductor Junctions
449
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...
449
01:22MOSFET: Enhancement Mode
454
Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations.
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
454
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.1K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.1K
03:51Molecular Orbital Theory II
19.6K
Molecular Orbital Energy Diagrams
19.6K
01:35Asymmetric Lipid Bilayer
7.5K
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
7.5K