Revealing Photo-electrochemical, Piezoelectric, and Ferroelectric Properties of γ-SnTe Monolayer via Density Functional Theory

Abstract

In this work, Density Functional Theory (DFT) calculations were performed to explore the photo-electrochemical, piezoelectric, and ferroelectric properties of the γ-SnTe monolayer. The optimized structure is confirmed to be dynamically and mechanically stable, exhibiting isotropic elastic behavior with an elastic modulus of 18.92 N/m and a shear modulus of 7.56 N/m. Electronic band structure analysis reveals that the γ-SnTe monolayer is an indirect semiconductor with a band gap of 2.56 eV, and the separation between charge carriers is clearly observed, with an effective mass mobility of approximately 0.44 m₀. Under biaxial strain, the band states continuously shift, optimizing redox potentials for surface chemical reactions. The material also demonstrates high piezoelectric coefficients, enabling efficient conversion of mechanical energy into electrical energy. Additionally, ferroelectricity is confirmed with a residual polarization of P_z = 5 pC/m and a low-energy switching barrier, making γ-SnTe highly suitable for low-power memory devices. These findings establish the γ-SnTe monolayer as a promising multifunctional material with potential applications in green energy technologies, electromechanical systems, and next-generation memory devices.