chat GPT가 설명하는 1T and 2H phases

Phase → coercivity → intrinsic property + geometry 

 

일반적으로, 물질의 crystal structure는 해당 물질의 물리적, 화학적 특성을 결정하는데 있어 주요한 역할을 한다. 예를 들어, 1T phase와 2T phase 사이의 crystal structue의 차이는 bandgap, carrier mobility, optical property 등 다양한 특성를 다르게 만들어 소자 응용등에 매우 중요한 역할을 한다. 

고체물리에서 1T, 2H phases는 각각 특정 물질(특히 TMDs)의 서로 다른 결정 구조를 나타낸다. 이 TMDs의 phase는 물질의 전기적, 광학적, 그리고 자기적 특성에 지대한 영향을 주어 TMD-기반 소자들의 디자인과 개발에 있어 주요하게 고려되는 것이다. 

 

 

1T phase (a metallic phase, trigonal prismatic phase)

1T phase는 hexagonal crystal structure를 가지며 1개의 전이 금속 원자가 두 레이어의 chalcogen atoms에 의해 샌드위칭 된다. 결과적으로 1개의 TM atom에 6개의 chalcogen atom이 붙어있는 꼴이 되며, TM과 atom의 nearest neighbor는 총 3개이고 각각이 120도의 각을 갖게된다. 이 1T phase는 또한 transition metal dichalcogenides (TMD) 구조로도 알려져있다.

wikipedia.org

 

$ MoS_{2}, MoSe2_{2}, WS2_{2} $ 등이 TMDs로서 해당 structure를 가지는 것으로 알려져 있다. 1T phase는 일반적으로 반도체의 성질을 가지며 독특한 전기적, 그리고 광학적 특성을 가진다. 그리고 이 특성을 이용해 전자소자나 에너지 저장과 관련된 분야의 응용에 유용하다.

 

2H phase (a semiconducting phase, the hexagonal phase)

2H phase는 crystal structure의 다른 종류로서, 2개의 transition metal layer가 3개의 chalcogen atom layer에 의해 샌드위칭 된 구조이다. 이 phase는 또한 alpha-phase로도 알려져 있으며, magnesium, zinc와 같은 hexagonal close-packed metal 등의 물질에서 발견된다. 2H phase는 reference crystal structure로서 종종 사용되는데 이는 성장시키기 쉽고 well-characterized 되기 때문이다. 이 crystal structure의 대표적인 물질로는 그래핀, $h-Bn$, $MoT_{2}$, $WTe_{2}$ 등이 있다.

with each layer rotated 60 degrees relative to the previous layer.

 

rdcu.be/c62g8

 

2H corresponds to 2 layers per H(exagonal) unit cell. 1T - one layer per (Trigonal) unit cell.

 

 

 

The 2H phase is also a hexagonal structure, but it has two atoms per unit cell, with one atom located at the center of the hexagon and the other atom located above or below the plane of the hexagon. This structure is commonly observed in materials containing group III-V elements (such as GaN and AlN), as well as in some transition metal dichalcogenides (such as MoS2 and WS2). The 2H phase is also sometimes referred to as the "wurtzite" structure.

 

 

 

The 1T phase refers to a hexagonal close-packed (HCP) structure in which one-third of the octahedral sites are occupied by the transition metal atoms, while the remaining two-thirds are occupied by the chalcogen atoms. This phase is commonly observed in transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2.

The 2H phase, on the other hand, is another hexagonal structure in which the transition metal and chalcogen atoms are arranged in a different way. In the 2H phase, the transition metal atoms are located in a trigonal prismatic coordination with the chalcogen atoms, forming a layered structure. This phase is also commonly found in TMDs, as well as in other materials like graphite.

Both phases have distinct electronic and optical properties, and their relative stability can be influenced by factors such as temperature, pressure, and doping. The understanding and manipulation of the crystal structures and their properties are important in various applications, such as electronics, optoelectronics, and catalysis.

 

 

In solid-state physics, the terms 1T phase and 2H phase refer to different crystal structures that certain materials can take on.

The 1T phase refers to a hexagonal crystal structure, also known as the trigonal prismatic or delafossite structure. This structure is characterized by layers of triangular prisms stacked on top of one another, with each prism containing a metal atom and three oxygen atoms. Materials that can exhibit the 1T phase include transition metal oxides and chalcogenides.

The 2H phase, on the other hand, refers to a hexagonal close-packed crystal structure. This structure is characterized by layers of hexagons stacked on top of one another, with each hexagon containing a metal atom. Materials that can exhibit the 2H phase include some metals and metal alloys, as well as certain semiconductors.

The distinction between the 1T and 2H phases is important in solid-state physics because the crystal structure can significantly affect a material's electronic, magnetic, and optical properties.

 

 

In solid-state physics, the terms "1T phase" and "2H phase" typically refer to different crystal structures of certain materials.

The 1T phase usually refers to a hexagonal crystal structure with a single layer of transition metal atoms (usually Group IVB or VB elements like titanium or vanadium) sandwiched between two layers of chalcogen atoms (usually sulfur, selenium or tellurium). Materials with this structure are called transition metal dichalcogenides (TMDs). Examples of TMDs in the 1T phase include MoS2, WS2, and TiS2. These materials have attracted significant attention in recent years due to their unique electronic and optical properties, which make them promising candidates for applications in electronics, optoelectronics, and energy conversion.

The 2H phase, on the other hand, refers to a hexagonal crystal structure with two layers of transition metal atoms stacked on top of each other, each surrounded by six chalcogen atoms. Materials with this structure are also TMDs, but they have different electronic and optical properties compared to their 1T counterparts. Examples of TMDs in the 2H phase include MoTe2, WSe2, and SnS2.

The difference between the 1T and 2H phases lies in their crystal structures, which affect their electronic and optical properties. For example, TMDs in the 1T phase typically have metallic or semiconducting behavior, while those in the 2H phase are usually indirect bandgap semiconductors. Understanding the crystal structures and properties of these materials is important for developing new applications and devices based on their unique properties.

 

 

 

The 2H phase, on the other hand, refers to a hexagonal crystal structure that has two layers of atoms per unit cell. This phase is also commonly observed in TMDs, as well as other materials such as graphite. In the 2H phase, the layers are stacked in an ABAB... sequence, 

The difference between these two phases is primarily in the number of layers per unit cell, which leads to differences in the crystal symmetry and electronic properties. These properties can have important implications for the behavior and functionality of materials in various applications.