表面国家在纳米晶-复合系统中调解三重能量传输
Jon A Bender1, Emily K Raulerson1, Xin Li2
1Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States.
Journal of the American Chemical Society
|May 31, 2018
概括
混合材料中的光子上升转换依赖于高效的能量传输. 研究人员发现PbS纳米晶体表面形成中介状态,有时阻碍这一关键的能量传递过程.
科学领域:
- 材料科学
- 纳米技术
- 摄影化学
背景情况:
- 混合有机:含有半导体纳米晶体 (NC) 和联体的无机材料显示出对光子上升转换的前景.
- 光子上升转换涉及NCs的红外光吸收,然后将能量转移到acenes以产生可见光.
- 在NC和acenes之间精确的能量转移机制尚不清楚.
研究的目的:
- 用TIPS-pentacene连接体进行功能化的PbSNCs激发电子动态的研究.
- 阐明纳米粒子能量转移的机制:用于光子上转换的乙烯系统.
- 了解NC表面在调节能量传输中的作用.
主要方法:
- 用超快速的短暂吸收光谱来研究TIPS- 素配体的PbSNC.
- 使用受约束密度函数理论 (DFT) 的计算.
- 暂时吸收线形状的分析与DFT结果是相关的.
主要成果:
- PbS NCs的光激发不会直接产生对TIPS-pentacene的三倍能量传递.
- 在40ps内形成一个中间状态,持续约100ns,然后产生TIPS-pentacene三重激素.
- 这种中间体可能是位于 PbS NC 表面的电荷载体,其中 DFT 显示了许多可以作为能量转移的促进器或陷的旋转三重体状态.
结论:
- PbS NC表面积极介导能量转移到乙烯配体.
- 在NC上的表面状态可以阻碍和促进能量传输.
- 优化基于NC的材料用于光子上转换和其他应用需要仔细考虑NC表面特性.
相关概念视频
01:16Surface Tension and Surface Energy
3.3K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
3.3K
01:21Transfer Function in Control Systems
1.6K
The transfer function is a fundamental concept in the analysis and design of linear time-invariant (LTI) systems. It offers a concise way to understand how a system responds to different inputs in the frequency domain. It serves as a bridge between the time-domain differential equations that describe system dynamics and the frequency-domain representation that facilitates easier manipulation and analysis.
To derive the transfer function, consider a general nth-order linear time-invariant...
To derive the transfer function, consider a general nth-order linear time-invariant...
1.6K
01:16Energy Transfer in Chemical Reactions
12.1K
Chemical reactions require sufficient energy to cause the matter to collide with enough precision and force that old chemical bonds can be broken and new ones formed. In general, kinetic energy is the form of energy powering any type of matter in motion. Imagine a person building a brick wall. The energy it takes to lift and place one brick on top of another is the kinetic energy—the energy matter possesses because of its motion. Once the wall is in place, it stores potential energy.
12.1K
04:10What is Energy?
59.3K
The universe is composed of matter in different forms, and all forms of matter contain energy. The different forms of energy on Earth originate from the Sun — the ultimate energy source. Plants capture light energy from the Sun, and, via the process of photosynthesis, convert it into chemical energy. This stored energy from plants can be harnessed in many ways. For example, eating plant products as food provides energy for our body to function, and burning wood or coal (fossilized...
59.3K
03:25Free Energy Changes for Nonstandard States
13.6K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
13.6K
02:56Free Energy and Equilibrium
27.3K
The free energy change for a process may be viewed as a measure of its driving force. A negative value for ΔG represents a driving force for the process in the forward direction, while a positive value represents a driving force for the process in the reverse direction. When ΔGrxn is zero, the forward and reverse driving forces are equal, and the process occurs in both directions at the same rate (the system is at equilibrium).
Recall that Q is the numerical value of the mass action...
Recall that Q is the numerical value of the mass action...
27.3K