The electronic structure formation of CuxTiSe2 in a wide range (0.04 < x < 0.8) of copper concentration

TL;DR

This study investigates how copper intercalation affects the electronic structure of TiSe2 across various concentrations, revealing charge transfer effects and core level shifts through spectroscopic analysis.

Contribution

It provides detailed experimental insights into the electronic structure evolution of Cu_xTiSe2 over a wide concentration range, highlighting charge transfer mechanisms.

Findings

Negative energy shifts in core levels with increasing Cu concentration

Evidence of dynamic charge transfer during covalent bond formation

Spectroscopic signatures of electronic structure modification

Abstract

An experimental study of the electronic structure of copper intercalated titanium dichalcogenides in a wide range of copper concentrations (x = 0.05 - 0.6) using the x-rays photoemission spectroscopy, resonant photoemission and x-rays absorption spectroscopy has been performed. Negative energy shifts of the Ti 2p and Se 3d core levels spectra and a corresponding decrease of the photon energy in Ti 2p absorption spectra with increasing concentration of copper have been found. Such sign-anomalous shifts may be explained by the shielding effect of the corresponding atomic shells as a result of the dynamic charge transfer during the formation of a covalent chemical bond between the copper atoms and the TiSe2 matrix.