Bilayer MSe₂ (M = Zr, Hf, Mo, W) performance as a hopeful thermoelectric materials

Abstract

Significant advancements in nanoscale material efficiency optimization have made it feasible to substantially adjust the thermoelectric transport characteristics of materials. Motivated by the prediction and enhanced understanding of the behavior of two-dimensional (2D) bilayers (BL) of zirconium diselenide (ZrSe2), hafnium diselenide (HfSe2), molybdenum diselenide (MoSe2), and tungsten diselenide (WSe2), we investigated the thermoelectric transport properties using information generated from experimental measurements to provide inputs to work with the functions of these materials and to determine the critical factor in the trade-off between thermoelectric materials. Based on the Boltzmann transport equation (BTE) and Barden-Shockley deformation potential (DP) theory, we carried out a series of investigative calculations related to the thermoelectric properties and characterization of these materials. The calculated dimensionless figure of merit (ZT) values of 2DBL-MSe2 (M = Zr, Hf, Mo, W) at room temperature were 3.007, 3.611, 1.287, and 1.353, respectively, with convenient electronic densities. In addition, the power factor is not critical in the trade-off between thermoelectric materials but it can indicate a good thermoelectric performance. Thus, the overall thermal conductivity and power factor must be considered to determine the preference of thermoelectric materials.

Recent advances in two-dimensional transition metal oxides and di-chalcogenides as efficient thermoelectric materials

“…The n-type ZrSe 2 has ZT value of 1.84 at carrier concentration of 7.85 × 10 12 cm −2 and for HfSe 2 is 3.83 at 2.37 × 10 12 cm 2 which is much higher than the bulk counterpart and monolayers. Jobayr et al [74] also investigated thermoelectric properties of 2D TMDCs MSe 2 (M = Mo, W, Hf, Zr) at room temperature by solving the Boltzmann transport equation and Bardeen-Shockley deformation theory. Thermal conductivity has a critical role to determine the thermoelectric properties.…”

Thermoelectric performance of 1T-ZrS2 bilayer using stacking engineering

“…However, 1T-phase have less thermal conductivity and gives the better results for energy conversion from thermal energy to electrical energy. Enhancement in the properties of monolayer is done by making homo/heterostructure bilayer [11][12][13][14], applying strain [15][16][17], using doping effect [18,19], quantum confinement (reducing the dimensions) by the formation of nanotubes [20,21] and creating the defects [22]. Song et al [23], studied the effect of strain for the thermoelectric performance of HfSe 2 monolayer and found that the maximum attained value of ZT for p-type doping is 2.5, at 300 K under 7.5% strained, whereas its value for unstrained monolayer was nearly 0.5.…”