Role of lithium intercalation in fluorine-doped tin oxide thin films: Ab initio calculations and experiment

Using a combination of experimental techniques and density functional theory (DFT) calculations, the influence of lithium insertion on the electronic and electrochemical properties of fluorine-doped SnO2 (FTO) is assessed. For this purpose, we investigate the electrochromic behavior of a commercial FTO electrode embedded in a solution of lithium perclorate (LiClO4). The electrochromic properties are evaluated by UV-vis spectroscopy, cyclic voltammetry, and chronoamperometry. These tests show that FTO exhibits electrochromism with a respectable coloration efficiency (eta = 47.9 cm(2)/C at 637 nm). DFT study indicates that lithium remains ionized in the lattice, raising the Fermi level about 0.7 eV deep into the conduction band. X-ray photoelectron spectroscopy (XPS) is used to study chemical bonding and oxidation states. XPS analysis of the Sn 3d core levels reveals that lithium insertion in FTO induces a shift of 350 meV in the Sn 3d states, suggesting that lithium is incorporated into the SnO2 lattice. Published under an exclusive license by AIP Publishing.

Automated summary

The influence of lithium insertion on the electronic and electrochemical properties of fluorine-doped SnO2 (FTO) was assessed using a combination of experimental techniques and density functional theory (DFT) calculations. The electrochromic properties of FTO were evaluated and it was found that lithium remains ionized in the lattice, raising the Fermi level and inducing a shift in the Sn 3d states.