Related Experiment Video
Updated: Jul 15, 2026
10:36
Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
Published on: January 21, 2016
11.4K
Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures
Kibum Kang1,2,3, Kan-Heng Lee4,5, Yimo Han4
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Nature
|September 28, 2017
Summary
Researchers developed a scalable method for creating uniform, atomic-precision semiconductor films using layer-by-layer assembly of 2D materials. This breakthrough enables high-quality heterostructures for advanced electronics and novel materials discovery.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Atomically precise semiconductor films are crucial for integrated circuits and materials discovery.
- Sequential layer-by-layer assembly of 2D materials (like graphene and transition-metal dichalcogenides) creates heterostructures with unique properties.
- Current methods are limited to small scales, hindering practical applications due to compromised material properties and interfaces.
Purpose of the Study:
- To develop a large-scale, vacuum-based layer-by-layer assembly method for fabricating wafer-scale semiconductor films.
- To achieve atomic-scale precision in vertical composition and maintain pristine interlayer interfaces.
- To demonstrate the fabrication of high-quality heterostructure films and devices for diverse applications.
Main Methods:
- Utilized sequential layer-by-layer assembly of two-dimensional building blocks under vacuum conditions.
- Employed van der Waals interactions for vertical stacking of atomically thin materials.
- Focused on maintaining the intrinsic properties of the 2D materials throughout the assembly process.
Main Results:
- Successfully generated wafer-scale semiconductor films with high spatial uniformity and pristine interfaces.
- Fabricated large-scale, high-quality heterostructure films and devices, including superlattices and tunnel devices.
- Demonstrated batch fabrication of tunnel device arrays with tunable resistance over four orders of magnitude.
- Created millimetre-scale ultrathin membranes and windows with tunable properties.
Conclusions:
- The developed method enables scalable, atomic-scale design of semiconductor films with high fidelity.
- The fabricated heterostructures and devices show potential for advanced electronics, including tunable tunnel diodes and ultrathin membranes.
- The detachable and versatile nature of the films opens possibilities for integration with optical and mechanical systems.
Related Concept Videos
02:22Structures of Solids
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:33Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
01:18Unit Cells
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...