Exploring the optoelectronic and thermoelectric properties of Ge1−xBixTe (at x = 12% and 24%) using GGA and GGA + SO approximation for renewable energy applications: a DFT study.

The growing material for optoelectronics, thermoelectric and renewable energy applications includes Ge_1−xBi_xTe (x = 12% and 24%). So, by using DFT and WEIN2k code, we calculated the electronic, optical and also thermoelectric properties of Ge_1−xBi_xTe (x = 12% and 24%). In GGA and GGA + SO, the band structures are studied which shows metallic nature. The entire geometric optimization process was carried out based on the cell parameters. Obtained results suggested that Ge_1−xBi_xTe (x = 12% and 24%) exhibits a predominantly metallic behavior. From through study of electronic charge density, we verified that the nature of examined material is primarily metallic. Bottom of the conduction and top of valence bands are due to Bi, Ge-p and Ti-p/s orbitals with minimal contributions of Bi-s orbitals states. We estimated optical parameters like optical conductivity, absorption coefficient, dielectric function, reflectivity coefficient, loss function, and refractive index for the polarized incident radiation. Finally, we calculated thermoelectric attributes like seebeck coefficient and others with the use of Boltzmann transport theory. The calculated optical and thermoelectric properties suggested that the doped system could be a potential material for optoelectronic applications with high absorption coefficient values in visible and ultraviolet region. This research provides valuable insights into the potential use of Ge_1-xBi_xTe for both x = 12% and 24% by using GGA + SO as promising candidate for renewable energy applications. [ABSTRACT FROM AUTHOR]