アモルフな単層の炭素における不規則に調整された伝導性
Huifeng Tian1, Yinhang Ma2, Zhenjiang Li1
1School of Materials Science and Engineering, Peking University, Beijing, China.
Nature
|March 1, 2023
まとめ
研究者は,成長温度を制御することによって,無形単層炭素 (AMC) フィルムの障害 (DOD) と電気伝導性を調整しました. 原子の構造と物質の性質を結びつけることで 2次元電子装置が生まれます
科学分野:
- 材料科学
- 凝縮物質物理学
- ナノテクノロジー
背景:
- 3Dの原子位置を決定する難しさのために,無形な固体の性質と原子構成 (乱雑度度 - DOD) を相関させるのは困難です.
- 二次元 (2D) システムは,アモルフな材料の研究を助け,原子イメージングのためのより単純なアプローチを提供します.
- 以前の研究では,無形単層炭素 (AMC) の原子構成を可視化しましたが,マクロスコピック特性との直接的なリンクはありませんでした.
研究 の 目的:
- アモルフな単層炭素 (AMC) フィルムにおける原子スケール構造とマクロスコピック特性との間の直接的な因果関係を確立する.
- 成長温度を制御することによって,AMCにおける乱雑度 (DOD) と電気伝導性を容易に調整することを実証する.
- 2次元無形材料の電気特性と微細構造パラメータを結びつけるフレームワークを開発する.
主な方法:
- 異なる温度で無形単層炭素 (AMC) フィルムの成長は,レーザーアシストデポジションを使用します.
- 原子構成,中距離順序 (MRO),ナノ結晶密度を視覚化するための原子解像度電子顕微鏡.
- マイクロ構造のパラメータに基づいて伝導性図を作成するための数値計算.
主要な成果:
- 中距離順序 (MRO) の変数範囲のジャンプ伝導性AMCは,熱分解の値温度で達成されました.
- 成長温度が25°C上昇すると,MROが失われ,板の抵抗が10^9倍に増加し,AMCは電気的に絶縁する.
- DODを完全に記述するために2つのオーダーパラメータ (MROとナノ結晶密度の存在/欠如) が特定されました.
結論:
- この研究は,2次元無形材料の電気伝導性と原子スケール構造 (乱雑度,MRO,ナノ結晶密度) を成功裏に結びつけています.
- 成長温度は,DODとAMCの伝導性を調節するための重要なパラメータとして特定されています.
- この研究は,無形材料の構造-特性関係に関する理解を深め,2次元無形電子機器への道を開く.
関連する概念動画
01:13Electrical Conductivity
1.2K
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
1.2K
02:37Metallic Solids
18.5K
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....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.5K
01:17Theory of Metallic Conduction
1.4K
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,...
1.4K
02:35Band Theory
15.3K
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,...
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
15.3K
02:18Network Covalent Solids
13.6K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
13.6K
01:22Semiconductors
761
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
761