First-principles study of the structural, electronic, optical, and thermoelectric properties of tetragonal K₂PdX₄ (X = Cl, Br) compounds for energy harvesting

In this study, a comprehensive analysis of the structural, electronic, optical, and thermoelectric properties of tetragonal K₂PdX₄ (X = Cl, Br) compounds has been conducted using a first-principle approach. The tolerance factors (0.96 for Cl and 0.97 for Br) indicate structural stability, while the formation energies ( \(-\) $-$ 1.76 eV for Cl and \(-\) $-$ 1.77 eV for Br) and the phonon dispersion results confirm their thermodynamic stability. The band gaps (1.87 eV for K₂PdCl₄ and 2.08 eV for K₂PdBr₄) computed from the band structures illustrate the potential utility of these compounds in various applications. The broad absorption band and minimal dispersion are calculated from the optical parameters. Moreover, the transport characteristics are analyzed in terms of electrical conductivity, thermal conductivity, Seebeck coefficient, and figure of merit. These results highlight the adaptability of these materials, indicating their potential for diverse applications, including thermoelectric and optoelectronic devices.