Strong electron-phonon interaction induced significant reduction in lattice thermal conductivities for single-layer MoS₂ and PtSSe

Electron-phonon interaction (EPI) has been widely suited in electrical transport properties, such as electrical resistivity in metals and electronic mobility in semiconductors. Nevertheless, its critical impact on lattice thermal transport has just been revealed in recent years, particularly for two-dimensional materials. Here, we emphatically report the carrier concentration dependent EPI effect on the lattice thermal conductivities for single-layer transitional metal dichalcogenide MoS₂ and PtSSe by first-principles calculations. In particular, when the EPI effect is considered, the lattice thermal conductivities at 300 K are significantly reduced by as much as 39% (42%) and 78% (55%) at 6.5 × 10¹³ cm⁻² for hole (electron) doping of MoS₂ and PtSSe, respectively. This abnormal suppression effect on thermal conductivity due to strong EPI for hole doping of PtSSe can be profoundly understood by its strong electron-phonon coupling strength and characteristic band structure. The former can be further rationalized by the breaking of the horizontal symmetry in PtSSe. Our work presents a deep insight into EPI effect on lattice thermal conductivity and provides a new perspective to search for strong EPI induced low thermal conductivity materials.