Ab-initio investigation of structural, electronic, thermoelectric and optical properties of Full-Heusler X2MnB (X = Ti, Zr) for energy harvesting applications.

High optical absorption coefficient and low reflectivity confirm use in solar cell applications. Material holds great potential for thermoelectrical applications. [Display omitted] • Electronic parameters reveal semiconducting nature. • Positive values of Seebeck coefficients indicate p-type character of X 2 MnB. • High optical absorption coefficient and low reflectivity confirm use in solar cell applications. In this manuscript comprehensive first-principles calculations have been presented for Full-Heusler X 2 MnB (X = Ti, Zr) compounds. This work includes detailed observations of the structural stability, origin of the transport phenomenon, optical properties, and electronic response. Structural parameters support the previous findings by confirming structural stability in the non-magnetic phase. Ti 2 MnB (Zr 2 MnB) valence band maxima and conduction band minima have bandgaps of 0.217 (0.301) eV and 0.181 (0.209) eV for PBE-GGA (mBJ) approximations which lie between L-L symmetry points. Due to the comparative measurements of the two states, the DOS results show that the Ti 1 /Zr 1 , Ti 2 /Zr 2 Mn e g , and t 2g states mainly contribute to the valence band region for Ti 2 MnB and Zr 2 MnB alloys, confirming their ionic nature. The computation of the overall electronic parameters' reveals semiconducting nature. Thermoelectric properties have been calculated as a function of temperature in the 100–1200 K range. The positive values of Seebeck coefficients specify p-type character of X 2 MnB While at 300 K, Zr 2 MnB and Ti 2 MnB showed the highest Seebeck coefficients, measuring roughly values of 268 (µK/V) and 243 (µK/V), respectively. These values suggest that the material exhibits high thermoelectric performance. Though high optical absorption coefficient and low reflectivity in the visible and ultra violet regions, confirms use of these materials in solar cell applications. These findings suggest that material holds great potential for use in thermoelectrical applications which can support in upcoming experimental considerations. [ABSTRACT FROM AUTHOR]