Synchrotron radiation photoemission study of Pb1−xCdxTe crystal with local structure

The paper presents photoemission study of core level binding energy shifts caused by local crystalline structure collapse in cubic Pb1−xCdxTe crystal. Photoemission spectra of two kinds of semiconductor samples are compared. The first one is ternary crystal of Pb0.94Cd0.06Te with the frozen rock salt structure where the crystalline local structure collapse is expected due to the difference of ion radii of Cd and Pb cations. The second sample was the CdTe(22nm)/PbTe(6nm)/CdTe(4μm)/GaAs(111)B nanostructure grown by molecular beam epitaxy (MBE) method, where crystalline local structure is not expected to be created. The photoemission spectra show that for the crystal with local structure the electron binding energies of cations are higher (e.g. +0.2eV) whereas for anions they are lower (e.g. −0.08eV) than in the multilayer structure. A model is proposed to explain obtained results by the local crystalline structure collapse in Pb0.94Cd0.06Te crystal.