First-principles calculations of the ultralow thermal conductivity in two-dimensional group-IV selenides

Thermoelectric Properties of Hexagonal M2C3 (M = As, Sb, and Bi) Monolayers from First-Principles Calculations

“…It is noted that the low frequency optical modes are alternating and softening with the three acoustic branches for the monolayer M 2 C 3 , resulting in strong acoustic–optical interactions. This is similar to the PbSe [50], which has strong anharmonic effects. The boundary frequency of lowest optical branch displays a decreasing trend with the following order: As 2 C 3 (4.18 THz) > Sb 2 C 3 (3.08 THz) > Bi 2 C 3 (2.12 THz).…”

Significant enhancement of the thermoelectric properties of CaP3 through reducing the dimensionality

“…5(b), we can see clearly that the large Grüneisen parameters mainly exist in low-frequency area, which is a typical behavior for the heat transport in materials. The average of acoustic Grüneisen parameters can be obtained by 66,67 ,…”

Ultralow lattice thermal conductivity and high thermoelectric performance of monolayer KCuTe: a first principles study

“…Herein, the phonon relaxation time can be obtained by the summation of various scattering processes. 48 Compared with some common TE materials, 17,41 we can see clearly that it shows a very short relaxation time (nearby 0.1 ps), leading to low lattice thermal conductivity. To further analyze its phonon relaxation time, the three phonon scattering phase space (P3) is presented as shown in the insert of Fig.…”

“…For its acoustic branches (ZA, TA, and LA), the average phonon velocities are 1.05, 0.82, and 0.83 km s À1 , respectively. Compared with the monolayer PbSe, 41 the phonon velocities of the KCuTe exhibits smaller phonon velocities, which can attribute to its at phonon dispersions. Based on the eqn (6), we can conclude that these small phonon velocities lead to low thermal conductivity.…”