Lineshapes in core-level photoemission from metals: II. and its transition metal intercalates

Abstract

SHAPER, a computer package for x-ray photoemission lineshape analysis, is applied to experimental data on 2H-TaS 2 and some of its transition metal intercalates, revealing that charge transfer into the conduction band resulting from intercalation affects the core-level lineshape by modifying the density of states at the Fermi energy. The observations are discussed in terms of the rigid-band model of intercalation. In order to emphasize the interactive character of the fitting process, and its strengths and limitations, a range of fits of increasing complexity is presented.

Epitaxial 2D MoSe2 (HfSe2) Semiconductor/2D TaSe2 Metal van der Waals Heterostructures

“…34−36 These shoulders are typical of trigonal prismatic coordinated layers, and they actually originate from excitations in the narrow conduction band. 34 It is inferred from Figure 4a that the experimental Ta 4f spectrum of the TaSe 2 /MoSe 2 sample resembles very well those recorded for a pure 2H-TaSe 2 phase, 35,36 and therefore, we claim the MBE formation of a clean 2H-TaSe 2 phase in the case where TaSe 2 is grown on MoSe 2 . In detail, three Ta 4f components are presented in the case of TaSe 2 /MoSe 2 sample, which were all assigned to the 2H-TaSe 2 phase.…”

“…Spin–orbit splitting and area ratio values of 1.91 eV and 4:3 were fixed for the fit. It should be noted at this point that in the case of pure 2H-TaSe 2 phase, the Ta 4f lineshapes are highly asymmetric, with clear shoulders on the high binding energy side of the main peaks. − These shoulders are typical of trigonal prismatic coordinated layers, and they actually originate from excitations in the narrow conduction band . It is inferred from Figure a that the experimental Ta 4f spectrum of the TaSe 2 /MoSe 2 sample resembles very well those recorded for a pure 2H-TaSe 2 phase, , and therefore, we claim the MBE formation of a clean 2H-TaSe 2 phase in the case where TaSe 2 is grown on MoSe 2 .…”

Lineshapes in core-level photoemission from metals: I. Theory and computational analysis

“…Following Wertheim and others [7] a more widely applicable model is developed here, accounting in greater detail for the range of possible final state excitations in the conduction band. This model is then used as the basis for an iterative fitting procedure for experimental data, implemented as a computer package-SHAPER-which is applied to the analysis from experimental data from the layered compound 2H-TaS 2 and some of its intercalates, and to 1T-and 4Hb-TaS 2 , in the following papers [8].…”

Photoemission from Intercalated Transition Metal Dichalcogenides

“…Charge transfer from the intercalant to the host layers is found also for these systems, but unlike for the corresponding compunds, the intercalant 3d-electrons are localized. The study by Hughes and Scarfe [128] of Ta 4f lineshapes in and related compounds also includes results from Mn and Co intercalates. These results are more closely described in the contribution by Hughes and Scarfe in this volume.…”