Strong Thermal Transport Anisotropy and Strain Modulation in Single-Layer Phosphorene

Using first-principles calculations and the nonequilibrium Greens function method, we investigate ballistic thermal transport in two-dimensional monolayer phosphorene sheet. A significant crystallographic orientation dependence of thermal conductance is observed, with room temperature thermal conductance along zigzag direction being 40% higher than that along armchair direction. Furthermore, we find that the thermal conductance anisotropy with the orientation can be tuned by applying strain. In particular, the zigzag-oriented thermal conductance is enhanced when a zigzag-oriented strain is applied but decreases when an armchair-oriented strain is applied; whereas the armchair-oriented thermal conductance always decreases when either a zigzag- or an armchair-oriented strain is applied. The present work suggests that the remarkable thermal transport anisotropy and its strain-modulated effect in single-layer phosphorene may be used for thermal management in phosphorene-based electronics and optoelectronic devices.