Exploring the potential of 2D magnesium-based semiconductors for next generation energy-efficient devices

Abstract Two-dimensional (2D) magnesium-based materials (Mg 2 X, X = Si, Ge, Sn) were systematically investigated using first-principles density functional theory (DFT) to explore their stability, electronic, thermoelectric, and optical characteristics. All three materials were found to be dynamically, mechanically, and energetically stable. Electronic band structure analysis revealed the indirect nature of semiconductors with band gap values ranging from 0.28 to 0.66 eV. A comprehensive evaluation of thermoelectric transport parameters, including Seebeck coefficient, electrical conductivity, and power factor, was performed as a function of temperature (300–800 K) and chemical potential (300 K) using Boltzmann transport theory implemented in the BoltzTrap code. Temperature dependent analysis showed exceptional power factors of 235 × 10 11 (mW mK −2 ) for Mg 2 Si at 300 K and 456 × 10 11 (mW mK −2 ) for Mg 2 Ge at 700 K. At specific chemical potential, Mg 2 Si demonstrated the highest Seebeck coefficient (1078 μV K −1 ), leading to a remarkable power factor of 683 × 10 11 (mW mK −2 ), emphasizing its potential for advanced thermoelectric applications. Optical characteristics were examined by calculating the dielectric constant, absorption coefficient, and optical conductivity. The real and imaginary parts of the dielectric function demonstrate the significant polarizability, semiconducting nature, and transparency of these materials. Absorption peaks in the near-infrared region, influenced by the incorporation of heavier X-atoms, suggest the potential of these materials for photovoltaic and IR sensor applications. We believe that the present theoretical findings filter out the potential of 2D Mg 2 X materials for future energy-efficient technologies.