Two-dimensional lattice thermal transport in graphene using phonon scattering mechanism: Application as heat management material for defence equipments

K. K. Choudhary
Indian Military Academy, Army Cadet College, UK, India

Keywords: Thermal conductivity, grapheme, phonon scattering

The extremely high electrical and thermal conductivity observed in graphene and its applications as heat management material in tanks, aircrafts, and nuclear submarines make it a suitable candidate for various defence applications. Thermoelectric properties of other materials can also be tuned by atomic substitution and nano-crystallization. Two-dimensional lattice thermal transport in graphene is investigated using phonon scattering mechanism. The in-plane lattice thermal conductivity is demonstrated by incorporating the scattering of phonons with defects, grain boundaries, electrons, and Umklapp phonon scatterings in the model Hamiltonian. High phonon mean free path of the order of few hundred nanometers is estimated which seems to be responsible for observed high thermal conductivity. It is experienced that heat transport by phonons and scattering rates are substantially different in a quasi-two-dimensional system such as graphene compared to the three-dimensional bulk crystals. We also analyzed the thermo electric figure of merit ZT which can be enhanced by nanostructuring thermoelectric materials. The key reason for increase in ZT is the reduction of thermal conductivity and increase in thermoelectric power by embedding ErAs nanoparticles in In0.53Ga0.47As crystalline semiconductors. The obtained results are in good agreement with the experimental data and show the dominant nature of phonon scatterings.