半导体金属有机框架中的工程带隙和光导:金属节点效应
James Nyakuchena1, Sarah Ostresh2, Jens Neu2,3
1Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States.
The journal of physical chemistry letters
|June 22, 2023
概括
金属THQMOF中的金属节点身份显著影响其结构和特性. 基于铁的MOF由于其最佳的带间隙和电荷转移状态而表现出最高的光导性.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 固态物理 固态物理
背景情况:
- 金属有机框架 (MOF) 是具有可调节性质的多孔材料.
- 进行MOF对电子和光电子应用有兴趣.
- 基于四基基 (THQ) 的MOF为电荷运输提供了潜力.
研究的目的:
- 系统地研究M-THQ MOF中的金属节点 (M = Fe,Ni,Cu,Zn) 及其结构性,光物理性和光导性质之间的相关性.
- 了解金属节点身份如何影响协调几何和由此产生的框架结构.
- 阐明电子结构和电荷运输特征之间的关系.
主要方法:
- 用不同的金属离子 (Fe,Ni,Cu,Zn) 合成M-THQ MOF.
- 使用X射线衍射进行结构性表征.
- 测量光物理性质,包括确定频段间隙.
- 光导度的测量. 光导度的测量.
- 时间分辨率光学光谱,X射线吸收光谱和太赫兹光谱来探测电子状态和电荷动态.
主要成果:
- 金属节点的身份决定了结构偏好:Cu 形成 2D Kagome 结构 (方形平面协调),而 Fe,Ni 和 Zn 形成 3D 结构 (八面协调).
- 在研究的材料中,Fe-THQ MOF 具有最小的带隙和最高的光导率.
- Fe-THQ MOFs具有长期存在的联体到金属电荷转移状态,归因于混合价值状态.
- 光谱技术证实了电子结构和电荷载体动态.
结论:
- 选择金属节点是调整基于THQ的MOF的光物理和光导特性的一个关键因素.
- 在需要高效的电荷传输和光相互作用的应用中,Fe-THQ MOF 显示出有前途的性能.
- 了解金属节点结构属性关系对于设计用于光电子的先进MOF材料至关重要.
更多相关视频
07:14Author Spotlight: Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
2.9K
06:45Author Spotlight: Characterizing Porous Materials for Aiding the Development of Robust Metal-Organic Frameworks with Adsorption Behavior
Published on: March 8, 2024
7.7K
相关概念视频
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
01:22Semiconductors
750
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...
750
01:27Biasing of Metal-Semiconductor Junctions
284
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
284
01:24Metal-Semiconductor Junctions
395
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...
395
01:01Energy Bands in Solids
953
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...
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...
953
01:12Fermi Level Dynamics
290
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...
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...
290