Thermoelectric, optoelectronic and magnetic properties of BaLn2ZnO5 (Ln = Eu, Pr, Sm) insulators by GGA/mBJ + U exchange-correlation approaches

• Physical properties of BaLn 2 ZnO 5 (Ln = Eu, Pr, Sm) compounds are studied by DFT. • The metallic nature of compounds is observed at low photon energies. • Calculated magnetic moment of BaEu 2 ZnO 5 is in good agreement with experiment. • It is strongly suggested to use these materials in the spintronic devices. • P-type BaEu 2 ZnO 5 and BaSm 2 ZnO 5 compounds are suitable for thermoelectric devices. Optoelectronic, magnetic and thermoelectric properties of BaLn 2 ZnO 5 (Ln = Eu, Pr, Sm) insulators are investigated by the full-potential linearized augmented-plane wave (FP-LAPW) method. The electronic results show that the BaLn 2 ZnO 5 compounds are wide-band-gap insulators and the optical threshold energies are suitable for the ultraviolet detectors and the LEDs. There is an inverse relation between the static dielectric function and the band gap value. The negative values of dielectric function with the high reflectivity are observed in the energy range of 10–12 eV. We find that the magnetic moment at the Ln sites decreases with a decrease in the number of electrons in the f state and the integer value of the total magnetic moment per unit cell confirms the non-metallic nature of BaLn 2 ZnO 5 compounds. The thermoelectric results by GGA + U show that p-type BaEu 2 ZnO 5 and BaSm 2 ZnO 5 compounds by 1 × 10 22 cm −3 doping can be used in thermoelectric devices.