超快的等离子增强热电子生成在Ag纳米集群/石墨异质连接处
Shijing Tan1, Liming Liu2, Yanan Dai1
1Department of Physics and Astronomy and Pittsburgh Quantum Institute, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
Journal of the American Chemical Society
|April 13, 2017
概括
石墨上的银纳米集群通过等离子激发有效地产生热电子. 这项研究揭示了用于能源应用的等离子异质连接中增强热电子生成和衰变的机制.
科学领域:
- 材料科学
- 表面科学
- 纳米技术
背景情况:
- 在金属异质连接处产生热电子是能量转换的关键.
- 石墨 (Gr) 的超快速光刺激会产生高温热电子.
- 金属纳米粒子中的等离子共振是高效的热电子发生器.
研究的目的:
- 研究银纳米集群 (AgNC) /石墨 (Gr) 等离子异质连接中的超快热电子生成和动态.
- 使用时间分辨率的二光子光辐射 (2PP) 谱法来探测这些过程.
- 了解等离子共振在增强热电子生成中的作用.
主要方法:
- 时间分辨率的双光子光辐射 (2PP) 光谱.
- 五秒激光激发可以调节波长.
- 在石墨上沉积Ag纳米集群.
- 电子结构计算
主要成果:
- 观察到2PP产量的2级增强,归因于3.6 eV的表面正常Mie等离子模式.
- 在G π*频段中从被占用的接口状态 (IFS) 和热电子中确定了贡献.
- 通过虚拟中间状态和通过等离子脱相的热电子群体确定IFS光辐射.
结论:
- 在 Gr 上的 Ag NC 创建了一个用于研究热电子动态的等离子异质连接模型.
- 这项研究阐明了增强热电子生成和衰变的机制.
- 这些发现对于光学-化学和电能转导应用具有重要意义.
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