NEXAFS – SODOBNA TEHNIKA ZA ŠTUDIJ MOLEKULSKIH ORBITAL V TANKIH PLASTEH

  • Gregor Bavdek Pedagoška fakulteta Univerze v Ljubljani
Keywords: X-ray absorption, NEXAFS, electronic structure, molecular orbitals, thin films

Abstract

In the present paper I present Near Edge X-ray Absorption Fine Structure, NEXAFS – the experimental technique nowdays being widely used in characterization of unoccupied electronic levels around Fermi level and chemical state of elements in homogeneous or heterogeneous thin layers. First I explain the excitation and relaxation mechanism of core level electrons based on brief quantum-mechanical theoretical background. I continue with basics of molecular orbital theory and corresponding transition selection rules for various combinations of molecular orbitals and polarization direction of X-rays. The usage of experimental technique is demonstrated in the case study of thin PTCDA film on Ge(001) surface, where the energy alignment of unoccupied molecular electronic states around Fermy level is determined, as well as the spatial orientation of PTCDA molecules with respect to substrate.

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Published
2021-09-30
How to Cite
1.
Bavdek G. NEXAFS – SODOBNA TEHNIKA ZA ŠTUDIJ MOLEKULSKIH ORBITAL V TANKIH PLASTEH. MatTech [Internet]. 2021Sep.30 [cited 2021Nov.28];55(5):637–648. Available from: https://mater-tehnol.si/index.php/MatTech/article/view/142