Exploring the structural, electronic, optical, and thermoelectric properties of potassium-based double perovskites K2AgXI6 (X = Sb, Bi) compounds: A DFT study.

• Theoretical study of Halide based double perovskite K 2 AgXI 6 (X = Sb, Bi) for optoelectronic and thermoelectric applications. • Electronic properties, density of states Optical dispersion and thermal parameters were studied using GGA+ mBJ. • We observed the indirect band gap of K 2 AgXI 6 (X = Sb, Bi) compound with values 0.7 eV–1.2 eV respectively. • K 2 AgXI 6 (X = Sb, Bi) compound shows maximum absorption invisible region makes it a potential candidate for optoelectronics. • We examined thermodynamically stable of studied compound which advocate the exceptional candidates for thermal devices. Currently, lots of studies are going to find out the quality of the materials that could be used in solar cells and energy storage devices because of their higher absorption and utmost conductivity. We used density functional theory simulations utilizing the full potential linear augmented plane-wave approach. The generalized gradient approximation functional intended for materials (PBE-GGA) was utilized to compute structural characteristics, although the modified Becke and Johnson (mBJ) potential functional was employed to compute optoelectronic and thermal properties. Their band gaps, may capture electromagnetic waves in the IR to the visible spectrum, rendering them appealing for optoelectronics devices. Achieving the highest values of transition in the visible region against photon energy in the optical characteristics suggested that investigated double perovskites could be used in solar cells. Additionally, the transport characteristics premeditated using the Boltzmann transport equation indicate that the temperature and chemical potential in K 2 AgSbI 6 to K 2 AgBiI 6 perovskites might be used to make them suitable for solar energy. In order to investigate the optoelectronic as well as thermoelectric characteristics of K 2 AgXI 6 (X = Sb, Bi) compounds used in energy storage devices. [ABSTRACT FROM AUTHOR]