超快速的电荷转移和混合激发形成在2D/0D异构结构中
Abdelaziz Boulesbaa1, Kai Wang1, Masoud Mahjouri-Samani1
1Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Journal of the American Chemical Society
|October 19, 2016
概括
研究人员发现2D/0D异构中超快的电荷转移. 这项研究探讨了二硫化单层和量子点中的混合激子,这对光电子至关重要.
科学领域:
- 材料科学
- 凝聚物质物理学
- 纳米技术
背景情况:
- 光诱导的界面电荷转移是光伏,光催化和光检测的关键.
- 双维过渡金属二基二氧化物 (2D-TMD) 为2D/2D异质连接提供独特的光学和电气性能.
- 2D/2D异构连接的局限性需要探索可调节电荷传输的新材料组合.
研究的目的:
- 研究2D/0D异构中的电荷转移动力学,用于光电子应用.
- 探索与2D-TMD接口的半导体量子点 (0D-QD) 的潜力.
- 描述这些新型异构结构中混合激子的形成和特性.
主要方法:
- 用5秒探测谱来研究超快速的电荷转移.
- 由二硫化单层 (2D-WS2) 和二氧化/硫化核心/外0D-QD组成的异构结构的表征.
- 为了补充超快动力学研究,使用了稳定状态测量.
主要成果:
- 在2D/0D异构接口上观察到45秒以下的电荷转移.
- 从2D-TMD到0D-QD的电子转移被确定为主要的电荷转移途径.
- 形成了约140 meV的混合激子,其中的电子在0D-QD中,而2D-TMD单层中则有孔.
结论:
- 2D/0D异构结构为高效和可调节的电荷传输提供了一个有前途的平台.
- 具有较低结合能量的混合激子的形成对光电子器件设计有重大影响.
- 这项工作为使用工程 2D / 0D 接口的先进光电子设备铺平了道路.
更多相关视频
05:39Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
10.4K
11:33All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
10.3K
相关概念视频
The Electrical Double Layer
100
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
100
Valence Bond Theory
11.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.5K
Hybridization of Atomic Orbitals II
50.0K
sp3d and sp3d 2 Hybridization
50.0K
Carrier Generation and Recombination
1.4K
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
1.4K
Metal-Semiconductor Junctions
1.2K
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...
1.2K
