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

Israel Perez; Victor Sosa; Fidel Gamboa; Jose Luis Enriquez-Carrejo; Juan Carlos Mixteco Sanchez

doi:10.1063/5.0085531

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

J Chem Phys. 2022 Mar 7;156(9):094701. doi: 10.1063/5.0085531.

Authors

Israel Perez¹, Victor Sosa², Fidel Gamboa², Jose Luis Enriquez-Carrejo³, Juan Carlos Mixteco Sanchez⁴

Affiliations

¹ National Council of Science and Technology (CONACYT)-Department of Physics and Mathematics, Institute of Engineering and Technology, Universidad Autonoma de Ciudad Juarez, Av. del Charro 450 Col. Romero Partido, C.P. 32310 Juarez, Chihuahua, Mexico.
² Applied Physics Department, CINVESTAV Unidad Mérida, km 6 Ant. Carretera a Progreso, A.P. 73, C.P. 97310 Merida, Yucatan, Mexico.
³ Department of Physics and Mathematics, Institute of Engineering and Technology, Universidad Autonoma de Ciudad Juarez, Av. del Charro 450 Col. Romero Partido, C.P. 32310 Juarez, Chihuahua, Mexico.
⁴ Department of Natural and Exact Sciences, CU Valles, Universidad de Guadalajara, Carr. a Guadalajara km. 45.5, C.P. 46600 Ameca, Jalisco, Mexico.

PMID: 35259891
DOI: 10.1063/5.0085531

Abstract

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 (η = 47.9 cm²/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.