单个金属纳米粒子的量子等离子体共振
Jonathan A Scholl1, Ai Leen Koh, Jennifer A Dionne
1Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA. jscholl@stanford.edu
Nature
|March 23, 2012
概括
量子尺寸的金属纳米粒子表现出独特的等离子共振,随着尺寸的减少,它们会转移到更高的能量. 这项研究揭示了小型银纳米圈中的量子效应,这对于催化和生物学至关重要.
科学领域:
- 纳米光子学和等离子学
- 量子力学和材料科学 量子力学和材料科学
背景情况:
- 金属纳米粒子表现出等离子体共振,在纳米光子学,生物学,传感,光谱学和太阳能等领域有应用.
- 量子尺寸纳米粒子 (<10 nm) 的等离子特性由于散射弱,金属-连接体相互作用和集体不均性,因此很难研究.
- 了解量子尺寸的等离子学对于催化和生物过程中的应用至关重要.
研究的目的:
- 在量子尺寸模式下研究单个无带的银纳米粒子的等离子共振.
- 为了将纳米粒子几何与等离子体共振特性相关联.
- 开发一个模型来解释观察到的量子等离子体行为.
主要方法:
- 使用偏差校正传输电子显微镜 (TEM) 成像.
- 使用单色扫描TEM电子能量损失光谱 (EELS).
- 分析了个别的,无带的银纳米粒子.
主要成果:
- 观察到,随着纳米粒子直径从20nm减少到<2nm,等离子体共振的蓝色转移到更高能量 (0.5 eV) 显著.
- 证明了纳米粒子几何和等离子体共振之间的直接相关性.
- 与经典预测的偏差是相当大的.
结论:
- 这项研究突出了小型金属纳米圈中的量子等离子体特性.
- 一个分析性的量子力学模型被开发出来,以解释观察到的能量转移.
- 这些发现适用于理解和利用催化活性和生物相关的纳米粒子.
相关概念视频
Atomic Structure
All matter is composed of atoms, the smallest individual units of elements. Each atom is made up of three subatomic particles: protons, neutrons, and electrons. Together, these three particles account for the mass and the charge of an atom.The History of Atomic TheoryThe first person to propose that everything on Earth is made up of tiny particles was the Greek philosopher Democritus, around 450 B.C. He used the term atomos, Greek for “indivisible,” from which the modern term “atom” is derived.
Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.Electrons Orbit the NucleusElectrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus...
Subatomic Particles
Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller subatomic particles: protons, neutrons, and electrons. These three particles account for the mass and the charge of an atom.
The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
Atomic Structure
The Greek philosopher Democritus proposed that everything on Earth is made up of tiny particles called atomos, Greek for "indivisible," from which the modern term "atom" is derived. In the 19th century, John Dalton proposed the atomic theory that is still largely correct today. He put forth five postulates to explain how atoms made up the world around us. (1) All matter is composed of infinitely small particles or atoms. (2) All atoms of a given element are identical to one another and (3) are...
Electron Behavior
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...


