Comparison of thermal conductivity in nanodot nanocomposites and nanograined nanocomposites

摘要

Most recent increases in thermoelectric performance have come by reducing thermal conductivity through nanostructuring. Therefore, current research efforts focus mainly on bulk nanocomposites. We simulated the thermal conductivities of two types of nanocomposites. We nanostructured Tl_(0.02)Pb_(0.98)Te by (ⅰ) embedding InSb nanodots in it, creating a nanodot nanocomposite, and (ⅱ) polycrystallizing it, creating a nanograined nanocomposite. The nanograined nanocomposite achieved lower thermal conductivity than did the nanodot nanocomposite due to the ability of the nanosized grains in nanograined nanocomposites to effectively scatter phonons over a wide range of frequencies, as long as the nanograined nanocomposite has sufficiently small grain size.