Photoemission Electronic Spectra οf CdTe/Pb_0.95Eu_0.05Te/CdTe

Abstract

The synchrotron radiation was used to apply tunable high energy X-ray photoemission spectroscopy for investigation of electronic structure of semiconductor nanostructure CdTe/Pb 0.95 Eu 0.05 Te/CdTe/GaAs(001) top part. The Pb 0.95 Eu 0.05 Te (6 nm thick) was buried under thin (22 nm) top layer of CdTe transparent for part of electrons photoemitted from Pb 0.95 Eu 0.05 Te buried layer. The top layer of CdTe was sputtered by Ar ion bombardment for surface cleaning and for leaving the thickness of CdTe more transparent for photoelectrons emitted from buried layer. For these thickness of the top layer the photoemission energy distribution curves corresponding to the valence band and core levels electrons of the buried layer atoms were measured with application of synchrotron radiation of energy hν = 3510 eV. The measured spectra corresponding to the buried layer atoms were observed in the valence band region and in the high binding energy region for core levels of Pb 4f , Pb 3d. The valence band contribution and core levels Cd 4d and Cd 3d were obtained mainly from top cover layer. Measured Te 4d, Te 3d and Te 4d spectra possess contribution as well from top cover layer as from the buried layer. The amount of Eu atoms was to small to be reasonable detected and presented in the paper.