Integrated theoretical and experimental study of boron antimonide: structural, optical, and thermoelectric properties

Abstract

Boron antimonide (BSb), a promising thermoelectric material from the binary Group III–V compounds, was synthesized using a hydrothermal method. It represents the first report on the chemical synthesis of BSb. This study combines experimental and theoretical methods, utilizing the full potential linearized augmented plane wave (FP-LAPW) and the Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) to calculate its structural, electronic, optical, and thermoelectric properties. The investigation explores the influence of different molar ratios of elemental boron and antimonide nanoparticles on the material structure and electrical and thermal properties. X-ray diffraction (XRD) revealed the zinc blende structure of BSb. UV-visible studies was used to determine the bandgap energy found the highest of 2.91 eV for the 1 : 2 ratio among other molar ratios. Hall measurements revealed an electrical conductivity of 6.52 × 10⁻³ Sm⁻¹ for the 1 : 2 ratio, while Seebeck measurements yielded a maximum Seebeck coefficient of −778 µV K⁻¹ for the 1 : 2 ratio indicating n-type behavior, which was consistent with both experimental Hall and Seebeck analysis. Using the BoltzTraP code, the Seebeck coefficient and power factor were determined to be 912 µV K⁻¹ and 0.387 nW m⁻¹ K⁻², respectively. The lowest experimental thermal conductivity of BSb was found to be 0.059 W m⁻¹ K⁻¹ for the 1 : 2 ratio due to the enhanced phonon scattering at the interfaces. These findings unveil intriguing thermal and electrical behaviors in the III–V boron group, showing promise for potential thermoelectric applications.