X射線光電子能譜學

Abstract

中文摘要 X射線光電子能譜學(X-ray photoelectron spectroscopy，XPS) 是以X射線為探測源，偵測被激發出具有元素特徵且動能低的光電子，以得到的電子能譜用於研究樣品表面組成和結構。因為它可以表示材料的組成成分、各組成成分所處的化學狀態，還可定量每種化學狀態的相對含量，所以又稱為化學分析用電子能譜學(Electron Spectroscopy for Chemical Analysis，ESCA)。 本文介紹XPS的基本知識，包括原理、儀器裝置、用途、定性分析、定量分析和譜圖的簡單介紹等。XPS是一種典型的表面分析技術，其原因在於，儘管X射線可穿透樣品很深，但只有樣品近表面一薄層發射出的光電子可逃逸出來，不會破壞樣品表層，這使得XPS常被用來作材料分析。一般檢測限為0.1at%，樣品的探測深度（d）由電子的逃逸深度（λ，受X射線波長和樣品狀態等因素影響）決定，通常，取樣深度d=3λ。對於金屬而言λ為0.5~3 nm；無機非金屬材料為2~4 nm；有機物和高分子為 4~10 nm[1]。

Abstract

X-ray photoelectron spectroscopy (XPS) is an X-ray as a source of detection, detecting the excitation of photoelectron with elemental characteristics and low kinetic energy, and the obtained electron energy spectrum is used to study the surface composition and structure of the sample. Because it can represent the composition of the material, the chemical state of each component, but also the relative content of each chemical state, it is also known as the Chemical analysis of electronic energy spectroscopy (ESCA). This paper introduces the basic knowledge of XPS, including principle, instrument device, use, qualitative analysis, quantitative analysis and brief introduction of spectral diagram. XPS is a typical surface analysis technique because, although X-rays penetrate deep samples, only photoelectron emitted from a thin layer near the surface of the sample can escape and do not destroy the surface of the sample, which makes XPS often used for material analysis. The general detection limit is 0.1at%, and the detection depth of the sample (d) is determined by the escape depth of the electron (λ, affected by factors such as x-ray wavelength and sample status), usually with a sampling depth of d=3λ. For metals,λis 0.5~3 nm; inorganic non-metallic materials are 2~4 nm; organic matter and polymers are 4~10 nm[1].