Enhanced mechanism of thermoelectric performance of Bi2Se3 using density functional theory

Abstract

Good thermoelectric performance is being sought to face major problems related to energy, especially in the concern of the usage of energy on environmental impact. In this work, we investigate the underlying mechanism to enhance the thermoelectric performance of bismuth selenide (Bi2Se3) by employing density functional theory (DFT) followed by the Boltzmann transport equation under relaxation time approximation. The structural, electronic, and thermoelectric properties were calculated and analyzed. From the analysis of combined results of thermoelectric properties and electronic properties as the function of the Fermi level, we found that the power factor of Bi2Se3 is improved by increasing electrical conductivity that contributed by the large density of states and light effective mass of charge carriers. The figure of merit, on the other hand, is enhanced by increasing Seebeck coefficient that contributed by heavy effective mass and decreasing thermal conductivity that contributed by low density of states. We also found that both power factor and figure of merit can be improved through n-type doping at 300 K and p-type doping at higher temperature (400 K and 500 K).

Eco-Friendly Cerium–Cobalt Counter-Doped Bi2Se3 Nanoparticulate Semiconductor: Synergistic Doping Effect for Enhanced Thermoelectric Generation

“…This result aligns with already reported findings substantiating the existing pathway of achieving higher zT in IV-VI compounds and other pnictogen chalcogenides [14]. Theoretical calculations have predicted Bi 2 Se 3 to demonstrate an excellent thermoelectric property from room to mid-temperature [15][16][17], This, thus, motivates us to experimentally explore the possible material design combination to improve the TE performance practically.…”

Prediction of two-dimensional bismuth-based chalcogenides Bi2X3(X = S, Se, Te) monolayers with orthorhombic structure: a first-principles study

“…This large interest is due to the materials optimal bandgap (1.3-2.3 eV) [16], strong spin-orbit coupling [17], absorption coefficient (105 cm −1 ) [18], highly anisotropic structure [19], and good thermoelectric properties [20]. Similarly, Bi 2 Se 3 belongs to the class of transition metal trichalcogenides and it has received prodigious attention to be exploited in thermoelectrics [21] and low-energy electronics [22]. Bi 2 Se 3 is a semiconductor with an energy bandgap in the range of 0.24-0.35 eV according to the experimental measurements and theoretical calculations [3].…”

Machine-learning guided prediction of thermoelectric properties of topological insulator Bi2Te3−xSex

“…On the contrary, DFT overestimates conductivities at higher temperatures, and a similar observation was found with the DFT study on Bi 2 Se 3 . 59 Analogously, the S EXPT ( T ) and S ML ( T ) show a decrease of S with temperatures in contrast with the S DFT ( T ) and a similar trend was witnessed for Bi 2 Te 3 and Bi 2 Te 2 Se. 55 As such, the random forest methodology enables reasonable first approximations of S as a function of temperature for the examined material.…”

“…The simulated s DFT increases, while S DFT decreases with the increase in temperature (Table 2), which is consistent with the reported s R-DFT (T) and S R-DFT (T) of the Bi 2 Se 3 and Bi 2 Te 3 . 55,59 However, the s EXPT (T) and s ML (T) show a decrease in s with temperature, i.e., Bi 2 Te 2 Se is insulating in contrast to the metal-like transport observed in the s DFT (T). In the experiment, the contribution to s of Bi 2 Te 2 Se might be suppressed by the bulk rather than the metal-like surface conduction.…”