X-ray Photoelectron Spectroscopy for GFET

Post date: Sep 25, 2013 4:20:31 AM

Recently, I tried to use XPS to analyze surface state of GFET. In here, let me mark what I have learned about this technique.

Since it is impossible for you to understanding all things about one technique, which maybe only be used seldom, I think wikipiedia is good choice for you to start.

For Chinese version: http://zh.wikipedia.org/wiki/X射线光电子能谱

For English version: http://en.wikipedia.org/wiki/X-ray_photoelectron_spectroscopy

After get a rough idea about XPS, you could search "XPS" and related words in Google or specific document collection website, such as baidu wenku. In my opinion, I prefer the following slides provided by Ms. Liu Fen in ICCAS,

http://wenku.baidu.com/view/bca239f7ba0d4a7302763a48.html

When I'm exposed to massive data about XPS obtained from MSE department, I felt stuck at first. I must thank senior members in our group, since it is their courage and help that motivate me to hold on.

For split peak in particular region, you could seek help from the oftware, XPSpeak4.1. You could download it for free in the following links:

http://www.yjal.com/yjal/viewthread.php?tid=12167

Now, let me talk about my feeling and understanding about XPS:

1. XPS is using a high energy X-ray photon to bombard the surface of materials being analyzed, and then using electron detector to count the counts and energies of electrons escaped from the surface;

2. XPS could be used to recognize chemical parameters due to particular binding energy of particular element, such as carbon, oxygen and boron (H and He could not be analyzed since the ASF is too low, this would be discussed later) and chemical state, such as sp2 and sp3 in carbon bonds;

3. The characteristic peak of chemical elements could be used to recognize elements, and area under the peak could be used to judge roughly the ratio between several elements. For analyze ratio, you need to refer to standard table and find atomic sensitivity factor (ASF) of different elements, since different elements have different photoelectron response and ASF should be multiplied with area under the peak to get “real area” to analyze ratio.

4. In a specific region, such as C1s, ratio between chemical bonds, such as C-C and C-O could be analyzed utilizing the area of different peaks. In here, I must stress why we could do this. Even we are investigating the inner electron, the chemical bond valence electrons forming could have impact on the binding energy on the inner electron.

Original Link: http://blog.sina.com.cn/s/blog_5d650197010115ys.html