Investigation of optical and thermoelectric characteristics of novel zintl-phase alloys CaZn₂X₂ (X = P, As, Sb) for green energy applications

Abstract This study examines the photovoltaic and thermoelectric response of calcium-based novel Zintl-phase alloys CaZn 2 X 2 (X = P, As, Sb). The structural, optoelectronics, and transport features of Zintl CaZn 2 X 2 (X = P, As, Sb) compounds have been analyzed using the full potential linearized augmented plane wave (FPLAPW) technique. Investigations on formation energy and phonon dispersion have confirmed the formation and dynamical stabilities. These compounds exhibit a semiconductor behavior, as their predicted bandgap values: 1.76 eV for CaZn 2 P 2 , 1.14 eV for CaZn 2 As 2 , and 0.32 eV for CaZn 2 Sb 2 . By investigating the optical properties, we have discovered their potential applicability in optoelectronic and photovoltaic devices, as evidenced by the optical response of these phases. The traditional Boltzmann transport theory has assessed transport characteristics against temperature and chemical potential. Significantly higher values of the Seebeck coefficient are achieved at room and elevated temperatures. Moreover, the power factor demonstrates a linear relationship with rising temperature. The remarkable optoelectronic properties and exceptional power factor values suggest that these materials are suitable for deployment in photovoltaic and transport devices.