Photoelectron spectra of 2H-TaS2and SnxTaS2

Abstract

Photoelectron spectra of Sn1/3TaS2 and SnTaS2 are reported and compared with spectra of 2H-TaS2 and SnS. It is possible to trace the charge transfer from Sn to Ta from the observed increase of the occupation of the lowest Ta 5d band and from the observed decrease of the positive charge on Ta. The charge transfer is the same in Sn1/3TaS2 as in SnTaS2. The data indicate the presence of two types of Sn atoms in SnTaS2. The Ta 4f peaks show an asymmetric broadening; and an anomalous intensity ratio of the 4f7 and 4f5/2 peaks. These effects are ascribed to shake-up effects involving excitations of 5d electrons. The average relaxation energy of a Ta 4f hole is found to be 1.1 eV.