我們的實驗主要是分析單色(monochromatic)同步輻射光引發吸附在溫度為30 K之Si(111)-7×7表面上的CF3Cl分子之光解作用(photolysis)。我們使用光電子譜技術(Photoelectron spectroscopy)來量測F(1s)蕊層光電子譜圖。在一系列F(1s)蕊層光電子能譜中，我們藉著CF3Cl分子的F(1s)信號隨光子曝露量增加而減少的情形，定量的估計出CF3Cl分子在光子照射下之光解離截面(Photolysis cross section)。我們認為CF3Cl分子的解離機制為入射光子激發F(1s)蕊層電子後，經歐傑衰減過程(Auger process)，造成C-F鍵截斷，而解離出F+離子。我們也發現入射光子能量為730 eV時，分子密度較高之表面的光解截面會大於分子密度較低的表面。但是光子能量為690 eV時，分子密度與光解離截面無關。我們認為因為能量730 eV的光子足夠游離CF3Cl之F(1s)蕊層電子而產生光電子，此光電子在分子密度較高的表面，將會誘發鄰近的CF3Cl分子而造成解離，最後導致分子之光解截面增加。另一方面能量690 eV的光子僅能激發F(1s)蕊層電子至11a1之反鍵結軌道，而不會產生光電子去誘發鄰近分子的解離。

We present an analysis of the photolysis of an adsorbed molecule induced by monochromatic synchrotron radiation. The system studied was CF3Cl adsorbed on Si(111)-7×7 at 30 K, and the technique employed was photoelectron spectroscopy (PES). The F(1s) core-level photoelectron spectra, under various photon exposure, show that the photolysis effect induced by the incident monochromatic synchrotron radiation photon occurs on adsorbed gas-solid system. It is interesting to estimate the photolysis cross section of adsorbed CF3Cl irradiation by photons from the sequential F(1s) core-level photoelectron spectra. Auger-Induced desorption are the major process responsible for the photodissociation of absorbed CF3Cl molecules.
At the incident photon energy of 730 eV, we have obtained the photolysis cross section of CF3Cl for the highest-dosed surface (~3.0×10-17 cm2), the medium-dosed surface (~2.2×10-17 cm2), and the lowest-dosed surface (~2.0×10-17 cm2). At the incident photon energy of 690 eV, we have obtained the photolysis cross section of CF3Cl for the highest-dosed surface (~1.4×10-17 cm2) and the medium-dosed surface (~1.5×10-17 cm2). For the highest-dosed surface the direct photodissociation and the adsorbed molecule-mediated dissociation mechanisms are responsible for the dissociation of adsorbed molecules by the incident photon energy of 730 eV. However for the medium- and the lowest-dosed surface only the direct photodissociation is responsible for the molecular dissociation. For the incident photon energy of 690 eV, only the direct photodissociation mechanism is responsible for the photolysis of adsorbed molecules of the medium- and the highest- dosed surface.

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