Temperature dependence of lattice thermal conductivity in bulk and nanostructures of lead telluride (PbTe)

Abstract

This paper examines the effect of temperature on the computational lattice thermal conductivity (LTC) of lead telluride (PbTe) in bulk and nanowire (NW) configurations utilizing a modified Morelli–Callaway model. Our method provides an accurate approach for predicting LTC across a range of temperatures, including very low temperatures, that strongly agree with experimental results. The model also enables the calculation of parameters that are difficult or impossible to measure experimentally, such as impurity levels, dislocation density, and electron concentration, which are essential for designing and optimizing nanoscale devices. We further examine the influence of NW size on various material properties of PbTe. It was found that mean bond length, lattice constant, and unit cell volume increase with the increase of NW size; while melting temperature, Debye temperature, group velocity, and density exhibited an opposite trend of decrement as the NWs become smaller. Noteworthy, LTC was seen to decrease when the size of NWs was changed to 192, 277, and 436 nm. These findings provide valuable insights into the nanoscale behavior of PbTe, shedding light on the interplay between structural and thermal properties. The results show that the modified Morelli–Callaway model could be a useful simulation tool for studying and predicting the thermal behavior of PbTe at the nanoscale level. This could help with the design of thermoelectric devices and other situations where precise control of thermal conductivity is important.