Phosphorous #
Orbitals and Energies #
Note – these are listed in BINDING ENERGY
P 2p ≈ 135 eV
P 2s ≈ 189 eV
P 3s ≈ 16 eV
P 3p ≈ 10 eV
Doublet Separations #
P 2p = 0.87 eV
Common Overlaps for P 2p #
Sr 3d – Pb 4f – Sn 4s – Tl 5s – Zn 3s – Eu 4d – Po 5p – Sm 4d
Theory and Background #
Phosphorus is essential in materials science due to its role in semiconductors, biomaterials, and functional coatings. It is a key component in phosphorene, a two-dimensional material with promising electronic and optoelectronic applications, and phosphate-based ceramics, which are widely used in biomedical implants and catalysis. Phosphorus is also crucial in LiFePO₄ battery materials, flame retardants, and corrosion-resistant coatings.
XPS analysis of phosphorous is typically performed on the P 2p region which may overlap with Sr 3d peaks or with the Zn 3s peak if the phosphorous has a high oxidation state. The doublet separation of P 2p is 0.86 eV.
Experimental Advice #
Phosphorous is commonly analysed in the context of bioglasses by XPS, where loss features, or high backgrounds from the Si 2p region may be seen. Ensure enough of a spectrum is taken at the low BE side to properly account for this Si contribution, and potentially use offsets to model the background.
Data Analysis Guidance #
Though phosphorous is a doublet peak, the small doublet separation means people often fit this as one species. While we would not recommend this in general, it is OK for basic quantification, and providing the peak shape is kept consistent across different species.
References #
- Data acquired by HarwellXPS
- Edmonds, M. T., et al. (2015). “Creating a stable oxide at the surface of black phosphorus.” ACS applied materials & interfaces 7(27): 14557-14562. Read it online here.
- Wang, Y. and P. M. Sherwood (2002). “Phosphorus pentoxide (P2O5) by XPS.” Surface Science Spectra 9(1): 159-165. Read it online here.
- Liu, K., et al. (2004). “Surface analysis of (NH2) 2CS‐treated GaP (001) by AES and XPS.” Surface and Interface Analysis: An International Journal devoted to the development and application of techniques for the analysis of surfaces, interfaces and thin films 36(8): 966-968. Read it online here.
