Ab initio study of mechanical and functional properties of novel CaZnC and CaZnSi half-Heusler materials

TL;DR

This study uses first-principles calculations to explore the structural, electronic, optical, thermoelectric, and mechanical properties of novel CaZnC and CaZnSi half-Heusler materials, revealing their potential in energy applications.

Contribution

It provides comprehensive ab initio analysis of CaZnC and CaZnSi, highlighting their stability, electronic structure, and energy conversion capabilities, which were not previously characterized.

Findings

CaZnC has a direct 1.186 eV band gap.

CaZnSi has an indirect 1.067 eV band gap.

Both materials show potential for photovoltaic and thermoelectric applications.

Abstract

This research work introduces the DFT through FP-LAPW+lo technique in WIEN2k software to obtain information about structural, thermoelectric, and optoelectronic characteristics of CaZnC and CaZnSi materials. The structural optimization was performed using PBE-GGA functional, while the rest of the characteristics were obtained with the PBE-GGA + TB-mBJ approach. The thermoelectric parameters were evaluated using BoltzTraP software. The elastic constants and other mechanical parameters were computed by utilizing the ELAST code within the WIEN2k software, while the thermodynamic characteristics were evaluated using the Gibbs2 program. The findings show a correlation between atomic composition and lattice dimensions while finding that CaZnC has a direct ($\Gamma$-$\Gamma$) band gap of $1.186$ eV, whereas CaZnSi has an indirect ($\Gamma$-$X$) band gap of $1.067$ eV. The optical studies of the compounds show potential applications for photovoltaics while the thermoelectric results find optimized power factors and figure of merit values for energy conversion performance. The elastic parameters of CaZnC and CaZnSi demonstrate material stability and brittleness. Lastly, the thermodynamic evaluations provide information about the thermal mechanism and disorder of the materials. As a result, this research work provides significant advancements in the understanding of the fundamentals of these compounds and highlights their promising applications in renewable energy technologies.