Effect of Embedding Nanoparticles on Thermal Conductivity of Crystalline Semiconductors: Phonon Scattering Mechanism

Abstract

We evolve a theoretical model for quantitative analysis of decrease in thermal conductivity (κ) by embedding ErAs nanoparticles in In0.53Ga0.47As crystalline semiconductors. The lattice thermal conductivity by incorporating the scattering of phonons with defects, grain boundaries, electrons, and phonons in the model Hamiltonian are evaluated. It is noticed that the ErAs nanoparticles provide an additional scattering mechanism for phonons. The embedding of ErAs nanoparticles in In0.53Ga0.47As crystalline semiconductors, the phonon scattering with point defects and grain boundaries become more efficient, which cause in the decrease of thermal conductivity up to half of its value of pure crystal. Conclusively, the temperature dependent of thermal conductivity is determined by competition among the several operating scattering mechanisms for the heat carriers. Numerical analysis of thermal conductivity from the present model shows similar results as those revealed from experiments.

Effective Thermal Conductivity of Spherical Particulate Nanocomposites: Comparison with Theoretical Models, Monte Carlo Simulations and Experiments

“…A reduction of the thermal conductivity as observed in Si-Ge is also found in other systems, for instance ErAs nanoparticles in In0.53Ga0.47. 3 In contrast, in SiO2-epoxy resin composite, is increasing with the nanoparticle volume fraction. Such a behavior may be interpreted by the much smaller value of the dimensionlessparameter in the case of SiO2-epoxy resin than for SiGe, due to a smaller mean free path.…”

“…The change in thermal conductivity has also been exploited to increase the figure of merit ZT of thermoelectric materials which behaves as the inverse of the heat conductivity. 3 The nanocomposite is generally made out of a homogeneous matrix in which nanoparticles are dispersed. For particles with diameters of the same order of magnitude or smaller than the phonon mean free path, the Fourier theory, based on the classical approach of thermodynamics, is not able to predict the heat flux thermal interactions between the matrix and the nanoparticles.…”

An extended thermodynamic model for size-dependent thermoelectric properties at nanometric scales: Application to nanofilms, nanocomposites and thin nanocomposite films

“…However, expression (14) does not account for non-local effects. These non-local effects are elegantly introduced in the framework of EIT by appealing to a hierarchy of fluxes ( ) , ( ) , ..., ( ) with ( ) identical to the heat flux vector , ( ) (a tensor of rank two) is the flux of , ( ) the flux of ( ) and so on.…”

“…Such materials know a huge variety of applications, such as heat conduction enhancement in polyesters [8] or energy storage systems [9], to mention a few. As far as goes nanostructured materials for thermoelectric systems [10][11][12][13], a decrease in the thermal conductivity is often sought for in order to increase the figure of merit ZT [5,6,14]. The figure of merit is not only inversely dependent on the thermal conductivity, but also depends on the electric conductivity, which are both size-dependent [7].…”

Interpretation of thermoelectric properties of Cu substituted LaCoO3 ceramics

“…The lattice thermal conductivity in continuum approximation follows [6] . ) 1 ( ) )( The relaxation time is proportional to the imaginary part of the phonon self-energy, expressed as ) ,…”