量子大小的拓绝缘体/半金属可以实现超高和宽带和吸收
Zhexue Chen1,2, Xinyu Sui2,3, Zhangqiang Li1,2
1CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China. zhangyong@nanoctr.cn.
Nanoscale horizons
|September 13, 2023
概括
研究人员开发了拓绝缘体 (Bi2Se3,Sb2Te3) 和半金属 (TiS2) 的新型超薄量子板. 这些材料表现出异常的非线性吸收,为先进的光学设备,如模式锁定激光器铺平了道路.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 纳米技术纳米技术
背景情况:
- 二维拓绝缘体和半金属是研究兴趣的领域.
- 具有内在性质的量子大小材料非常受欢迎,但未被充分探索.
研究的目的:
- 报告高产的生产的单层量子板 (QSs) 的拓绝缘体 (Bi2Se3,Sb2Te3) 和半金属 (TiS2) 与sub-4纳米侧面尺寸.
- 调查这些新型QS的线性和非线性光学特性.
主要方法:
- 单层Bi2Se3,Sb2Te3和TiS2量子板的合成.
- 量子板的特性,包括光发光的特征.
- 制造QSs-多聚甲酸 (PMMA) 混合薄膜.
- 测量非线性和吸收 (NSA) 性能.
主要成果:
- 成功生产了高产量,单层QS,侧面尺寸低于4nm.
- 在QS分散中观察到显著的光发光,取决于激发波长,度和溶剂.
- 在QSs-PMMA混合膜中证明了异常的非线性和吸收 (NSA).
- 在具有宽带特征的Bi2Se3 QSs-PMMA中实现了创纪录的NSA性能,包括高调制深度 (高达72.4%) 和低和强度 (低至0.49 MW cm^-2).
结论:
- 开发的量子板代表了量子尺寸拓材料的重大进步.
- Bi2Se3 QSs-PMMA的非凡NSA性能突显了它们在模式锁定激光器和其他光学技术中的应用潜力.
相关概念视频
Semiconductors
738
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...
738
Fermi Level Dynamics
278
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...
278
Band Theory
15.2K
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,...
15.2K
Types Of Superconductors
1.0K
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
1.0K
Energy Bands in Solids
920
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...
920
UV–Vis Spectroscopy: Molecular Electronic Transitions
1.6K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.6K


