Effect of nanoinclusions on the lattice thermal conductivity of SnSe

We theoretically investigate the effect of nanoparticle(NP) inclusion on the lattice thermal conductivity (kappa ( l )) of SnSe matrix. The theoretical approach involves the prediction of kappa ( l ) by varying the radius (R), density (D (1)), and volume fraction (epsilon) of NP in SnSe matrix. NP has strong anisotropic effect on the lattice thermal conductivity reduction along the crystallographic direction. We observe the existence of an optimal NP volume fraction that minimizes the nanocomposite's thermal conductivity. At room temperature, this value is found to be epsilon = 0.317 for which lattice thermal conductivity reduces by 35% with NP (R = 5 nm) compared to pure SnSe. An enhancement in the figure of merit (ZT) around room temperature opens up new opportunities for thermoelectric power generation at moderate temperatures. Even larger enhancement is possible in polycrystalline SnSe which will be helpful for thermoelectric devices.