Non-adiabaticity in surface chemical reactions
Non-adiabaticity in surface chemical reactions
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DOI：
10.1016/j.susc.2008.12.037
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发表时间：
2009-06-01
期刊：
影响因子：
1.9
通讯作者：
Hasselbrink, Eckart
中科院分区：
文献类型：
--
作者：
Hasselbrink, Eckart
表面的化学反应可能会耗散能量，从而激发金属基底中的电子-空穴对。当 Au 顶部电极暴露于原子氢束时，通过测量 Ta-TaOx-Au 隧道结中的隧道电流，可以实现化学感应热载流子的直接检测。在通量为0.1 ML s(-1) 的氢气暴露过程中观察到1 nA cm(-2) 的电流。瞬态与反应动力学相关，使我们能够识别引起电子激发的基本反应步骤，并通过观察到的电流进行监测。使用 Pt 作为顶部电极材料，观察到明显不同的瞬态。向传感器施加偏置电压可以对电子激发进行光谱分析。这些实验提供了对表面各种反应步骤的非绝热性的详细见解。 (C) 2009 Elsevier B.V. 保留所有权利。
Chemical reactions at surface may dissipate energy exciting electron-hole pairs in the metal substrate. Direct detection of the chemically induced hot charge carriers may be achieved by measuring the tunnel current in Ta-TaOx-Au tunnel junctions when the Au top electrode is exposed to an atomic hydrogen beam. A current of 1 nA cm(-2) Was observed during a hydrogen exposure with a flux of 0.1 ML s(-1). The transient is related to the reaction kinetics and allows us to identify the elementary reaction steps causing the electronic excitations which are monitored by the observed current. Using Pt as top electrode material a markedly different transient is observed. Applying a bias voltage to the sensor allows spectroscopy of the electronic excitations. The experiments provide detailed insights into the non-adiabaticity of various reaction steps at a surface. (C) 2009 Elsevier B.V. All rights reserved.