通过控制在WS2/WSe2异构结构中的Spin-Triple和Spin-Singlet间层激发电的全光谷极化开关
Yue Hu1, Xinglin Wen1,2, Jiamin Lin3
1School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Nano letters
|July 13, 2023
概括
研究人员开发了一种简单的全光学方法,使用微球腔来控制过渡金属二基化物 (TMD) 中的介层激子 (IX) 排放. 这种技术增强了IX发射,并使室温谷极化切换具有高开/关比.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 光电学是指光电子产品.
背景情况:
- 过渡金属二甲基化物 (TMD) 异构结构中单位和三位层间激子 (IX) 的选择性控制通常需要复杂的装置和低温.
- 现有的IX控制方法通常涉及电场或磁场,限制了实际应用.
研究的目的:
- 展示一种简单的全光学方法,用于在TMD异构结构中选择性增强单重和三重IX辐射.
- 为了实现对IX排放物种和强度的室温控制.
- 开发一个具有高开/关比的全光谷偏振开关.
主要方法:
- 使用WS2/WSe2异构结构与SiO2微球腔相结合.
- 使用角度分辨率光发光谱学来分析IX辐射.
- 利用腔的普尔塞尔效应来增强特定的IX过渡.
主要成果:
- 通过对微球腔的光学合来实现单元和三元IX辐射的选择性增强.
- 描述了单极和三极IX的过渡双极时刻,揭示了它们在外平面贡献中的差异.
- 在室温下,同时增强IX排放强度和控制排放性IX物种.
- 一个全光学谷极化开关成功实现了创纪录的高开/关比为35.
结论:
- 使用微球腔的全光学方法提供了一种简化和有效的方法来控制TMD异构结构中的IX辐射.
- 这种技术使IX物种和强度的室温操纵成为可能,为新型光电子设备铺平了道路.
- 展示的谷极化开关凸显了这种方法在先进光子应用中的潜力.
相关概念视频
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
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.1K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.1K
01:16Biasing of P-N Junction
613
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
613
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
03:24Hybridization of Atomic Orbitals I
47.4K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
47.4K
01:17Spin–Spin Coupling: One-Bond Coupling
1.0K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.0K