Summary Stability and dynamics of structure, mechanical and thermoelectric properties of SiH monolayer have been reported in this work. After confirming the stability apprehensions, electronic structure calculations present the SiH as an indirect semiconducting monolayer with a bandgap of 2.19 eV. Calculations on elastic constant, deformation potential constant, effective mass, relaxation time, and mobility of charge carriers have been done to get the exact value of thermoelectric parameters. We analysed the variation of Seebeck coefficient, electrical conductivity and electronic thermal conductivity with respect to chemical potential at different temperatures and found that the high value of Seebeck coefficient and electrical conductivity along with low electronic thermal conductivity leads to a high value of ZeT ꞊ 2.185. SiH monolayer is being reported for the first time as a thermoelectric material and calculated thermoelectric properties show that SiH monolayer can be used efficiently in the field of thermoelectricity.

Summary The structural, electronic, and thermoelectric transport properties of two‐dimensional (2D) NiO2 are investigated with the help of combined density functional theory and semi‐classical Boltzmann transport equations. Formation energy and phonon dispersion are in support of the chemical and dynamical stability of NiO2. Calculations reveal the semiconducting nature of the monolayer with indirect band‐gap of 1.65 eV. Based on the electronic band structure, the variation of transport properties with chemical potential (μ) at different temperatures (300, 500, and 700 K) are explored. Elastic constant, deformation potential constants, and effective masses are calculated to obtain the exact value of relaxation time and mobility of charge carriers at different temperatures. The maximum value of Seebeck coefficient and electrical conductivity is −2674 μVK−1 and 9.92 × 105 Sm−1, respectively, while the peak value of electronic thermal conductivity is 7.22 Wm−1 K−2 leading to ZT of 0.506. The transport properties indicate that the monolayer can be used efficiently for collective response of transport properties.

In the last few decades, the varieties of semiconductors have been explored for electronic and thermoelectric applications. As per such motivations, in present research work, the investigation of two quaternary Heuslers (QHs) i.e. LiHfCoGe and LiHfCoSn (having semiconducting nature) have been carried out for structural, electronic, vibrational, elastic, mechanical, thermodynamical and thermoelectric properties within the computational approach of Density Functional Theory (DFT) and Boltzmann transport equations. Both the alloys are enriched with p-type semiconducting nature along with the dynamical stability that crystallizes in FCC cubic structure of F-43m space group. The high Seebeck coefficient values are like of excellent fundamental thermoelectric character. The high melting points expose their scope in the high-temperature regions. Even the figure of merit (ZT) is of average range but better than many of the compounds of the same kind for the constant relaxation time approximations however all the thermoelectric properties are also measured and presented at the calculated relaxation time by deformation potential theory. The effect of spin orbit coupling is also studied on the thermoelectric properties. The practical utilization of the materials can be evaluated from the elastic and mechanical properties that are favorable to manufacturing efficient and reliable Thermoelectric Modules in high-temperature range. A sufficient discussion of thermodynamic properties is carried out to give an image of the internal lattice thermal vibrations. It is worth mentioning that the present research work has the standards to be discussed in experimental research areas of energy conversion techniques.

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