AVS 56th International Symposium & Exhibition
    Applied Surface Science Wednesday Sessions
       Session AS-WeM

Invited Paper AS-WeM5
Hydrogen Quantification at Surfaces by Electron Spectroscopy

Wednesday, November 11, 2009, 9:20 am, Room C2

Session: Electron Spectroscopies
Presenter: F. Yubero, CSIC, Spain
Correspondent: Click to Email
The quantification of H at the surface is a subject of key importance. However, direct quantification of this element at the surface region (<2-3 nm) is not an easy task. Note for example that H does not show photoemission peaks in standard surface analysis by XPS. An indirect way to quantify it is by means of High Resolution Electron Energy Loss Spectroscopy, but only those H atoms participating in the vibrational absorption spectra would be observed. It is also possible H quantification with surface sensitivity by means of Nuclear Reaction Analysis, but this technique is not easily available.

Recently it has been proposed a method to quantify the H content at the surface of a-C:H samples based in the analysis of elastically backreflected electrons with primary energies about 1500 eV [1,2]. It is based on the fact that the recoil energy of the incident electrons depends on the atomic mass of the atoms located at the surface that act as scatter centres. Fairly consistent analysis were found for a-C:H materials and polymer surfaces. [1,2]. This new strategy of analysis has also been use to distinguish between H and deuterium (D) at the surface of ice water. The possibilities of this new technique, in combination with standard X-ray photoemission, for example for the study of polymer surfaces that have been labelled with either H or D, will be discussed.

[1] F. Yubero, V.J. Rico, J.P. Espinós, J. Cotrino, A.R. González-Elipe, Applied Physics Letters 87, 084101 (1-3) (2005)

[2] V.J. Rico, F. Yubero, J.P. Espinós, J. Cotrino, A.R. González-Elipe, D. Garg, S. Henry, Diamond and Related Materials 16, 107-111 (2007)