ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Stable lead-free double perovskites Li₂MoZO₆ (Z = Si, Ge, Sn) for solar energy harvesting: a density functional theory study

Arshad khan, Naimat Ullah Khan, Fakhar Anjam, Amjad A. Almunyif, Javed Iqbal, and Khadim Ullah

Department of Physics, University of Science and Technology Bannu, Bannu, Pakistan

E-mail: nukhan.ustb@gmail.com

Received: 1 March 2025  Accepted: 23 August 2025

Abstract:

This study investigates the stability and potential of lead-free double oxide perovskites Li₂MoZO₆ (Z = Si, Ge, and Sn) for solar energy harvesting. Density functional theory (DFT) calculations using the WIEN2k package reveal that all three compounds exhibit cubic symmetry (space group Fm-3m). Additionally, tolerance factor analysis, phonon spectra, formation energy calculations, and ab initio molecular dynamics simulation verified the structural, dynamic, thermodynamic, and thermal stability of the compounds at room temperature. Electronic properties calculated using the TB-mBJ and HSE06 potentials reveal that Li₂MoZO₆ (Z = Si, Ge, Sn) compounds exhibit semiconducting behavior, with band gaps of (1.78, 1.64, and 1.34) eV, respectively, from TB-mBJ calculations, and corresponding values of approximately (2.10, 1.85, and 1.64) eV from HSE06 calculations. Elastic constants calculations demonstrate the mechanical stability, ductility, and anisotropy of the given compounds. The analysis of optical properties reveals high absorption coefficients and significant optical conductivity within the visible and near-UV spectrum, indicating the potential applications of the simulated compounds in photovoltaic and optoelectronic.

Keywords: DFT; Double perovskite; Optoelectronics; Semiconductor; Energy; Band gap; Applications

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04349-1

Chemical Papers 79 (12) 8763–8779 (2025)