Silicon

Silicon is extensively studied by XPS due it’s effectiveness as a substrate and the versatility of the oxide as a catalyst support. The 2p region is the major emission where there is a small doublet separation (0.6 eV) and the oxidised form of silicon may exhibit a larger FWHM than that of the elemental form (Figure 1).

Figure 1: Si 2p region of SiO2 overlayer on Si substrate(1)

Silicon species exhibit marked differences in binding energy, rendering deconvolution a relatively trivial task. A range of common binding energies may be found in Table 1.

Species Binding energy / eV Charge ref. Ref.
Si 99.5 Au 4f / 83.94 2
SiO2 103.5 Au 4f / 83.94 2
SiC 100.5 Au 4f / 83.8 3
SiN 102
Silicone 102.4
Table 1: Si binding energies

Silicon 2s peaks are also relatively large, and may be of use where Si 2p overlaps with another emission (Figure 2).

Figure 2: Si 2s region(1)

References

  1. Data acquired by HarwellXPS
  2. Jensen, D. S., et al. (2013). “Silicon (100)/SiO2 by XPS.” Surface Science Spectra 20(1): 36-42. Read it online here.
  3. Miyoshi, K. and D. H. Buckley (1982). “XPS, AES and friction studies of single-crystal silicon carbide.” Applications of Surface Science 10(3): 357-376.. Read it online here.