Figure6

Figure 6. Contributions of different phonon modes (ZA, TA, LA, and Optical) to $$ {\kappa_{{\rm{L}}}} $$ of the PbSe/PbTe monolayer heterostructure, including four-phonon scattering in both the x and y directions. Solid-filled bars represent results obtained using the three-phonon scattering model, while hatched-filled bars denote results considering four-phonon scattering. ZA: Out-of-plane; TA: transverse; LA: longitudinal.