Binding Energy and Dissociation Barrier: Experimental Determination of the Key Parameters of the Potential Energy Curve of Diethyl Ether on Si(001).
Binding Energy and Dissociation Barrier: Experimental Determination of the Key Parameters of the Potential Energy Curve of Diethyl Ether on Si(001).
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结合能和解离势垒：二乙醚在 Si(001) 上势能曲线关键参数的实验测定。
DOI：
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发表时间：
2015
影响因子：
5.7
通讯作者：
U. Höfer
中科院分区：
文献类型：
--
作者：
M. Reutzel;M. Lipponer;M. Dürr;U. Höfer
以乙醚(Et2O)在Si(001)表面的模型体系为例，对有机分子在半导体表面势能曲线的关键参数--中间态结合能和解离势垒进行了实验研究。Et2O通过键合的中间体吸附，然后通过乙醚裂解转化为共价连接的终态。利用光学二次谐波方法，在不同温度下实时跟踪了这一热激活到终态的转变，并测定了相应的能垒ϵa=0.38±0.05 eV和指前因子νa=10(4±1)S(-1)。通过对初始粘着几率的分子束实验，求出了脱附能ϵd和ϵa的差值，从而确定了中间态的结合能(0.6 2±0.0 8 eV)。从一般化学趋势以及半导体表面吸附反应的更广泛适用性方面对结果进行了讨论。
The key parameters of the potential energy curve of organic molecules on semiconductor surfaces, binding energy of the intermediate state and dissociation barrier, were experimentally investigated for the model system of diethyl ether (Et2O) on Si(001). Et2O adsorbs via a datively bonded intermediate from which it converts via ether cleavage into a covalently attached final state. This thermally activated conversion into the final state was followed in real-time by means of optical second-harmonic generation (SHG) at different temperatures and the associated energy barrier ϵa = 0.38 ± 0.05 eV and pre-exponential factor νa = 10(4±1) s(-1) were determined. From molecular beam experiments on the initial sticking probability, the difference between the desorption energy ϵd and ϵa was extracted and thus the binding energy of the intermediate state was determined (0.62 ± 0.08 eV). The results are discussed in terms of general chemical trends as well as with respect to a wider applicability on adsorbate reactions on semiconductor surfaces.