Excellent Thermoelectric Performance of 2D CuMN2 (M = Sb, Bi; N = S, Se) at Room Temperature

Abstract

2D copper-based semiconductors generally possess low lattice thermal conductivity due to their strong anharmonic scattering and quantum confinement effect, making them promising candidate materials in the field of high-performance thermoelectric devices. In this work, we proposed four 2D copper-based materials, namely CuSbS2, CuSbSe2, CuBiS2, and CuBiSe2. Based on the framework of density functional theory and Boltzmann transport equation, we revealed that the monolayers possess high stability and narrow band gaps of 0.57~1.10 eV. Moreover, the high carrier mobilities (102~103 cm2·V−1·s−1) of these monolayers lead to high conductivities (106~107 Ω−1·m−1) and high-power factors (18.04~47.34 mW/mK2). Besides, as the strong phonon-phonon anharmonic scattering, the monolayers also show ultra-low lattice thermal conductivities of 0.23~3.30 W/mK at 300 K. As results show, all the monolayers for both p-type and n-type simultaneously show high thermoelectric figure of merit (ZT) of about 0.91~1.53 at room temperature.

Growth of a CuSbSe2 single crystal by the Bridgman technique and its utility as a photodetector and thermoelectric material

“…At a temperature of 543 K, the observed value of power factor is 0.00672 μW cm −1 K −2 . 50 The rise in the power factor with temperature can be attributed to the increased electrical conductivity and Seebeck coefficient. The figure of merit ( zT ) is calculated using the below equation (eqn (7)).where ‘ S ’ denotes the Seebeck coefficient, ‘ σ ’ represents the electrical conductivity, ‘ κ ’ is the thermal conductivity and ‘ T ’ is the temperature.…”

“…At a temperature of 543 K, the observed value of power factor is 0.00672 mW cm À1 K À2 . 50 The rise in the power factor with temperature can be attributed to the increased electrical conductivity and Seebeck coefficient. The figure of merit (zT) is calculated using the below equation (eqn (7)).…”