Effect Of Silicon Concentration On Phonon Thermal Conductivity Of Silicon-germanium Alloy

Phonon scattering from point defect is one of the key mechanisms affecting the thermal transfer for electronic insulators,in which the phonon frequency and the dope concentrations are significant factors.This paper aims at the effect of silicon concentration on the phonon thermal conductivity's actuality and development with brief introduction and discussion at first.Then the thesis introduces the theory of phonon thermal conductivity,and makes it out with rigidity model.Finally,analyze the effect of silicon concentration on phonon thermal conductivity of silicon germanium alloy.In the course of the study,according to the similarity between silicon and germanium,linear interpolation is used to calculate silicon and germanium parameters,and Callaway model and Holland model are used as thermal conductivity calculation model.Then,Gauss Integral formula is utilized to calculate phonon thermal conductivity formula,which can not be integral.Finally,utilize Matlab to calculate the intrinsic thermal conductivity and phonon thermal conductivity,map, compare,analyze.Compare the ratio of intrinsic thermal conductivity and phonon thermal conductivity with different temperatures,study shows that with temperature increases,the effect of silicon concentration on phonon thermal conductivity of alloy gradually weakened.When the silicon concentration is near 65%,the thermal conductivity of silicon germanium alloy obtains the minimum.Further,Klemens model is used to analyze the effect of relevant parameters on intrinsic thermal conductivity calculation.Analysis shows that when the thermal conductivity obtains the minimum,silicon concentration is related with Gruneisen coefficient.Finally, introduce the application conditions of Klemens model,Callaway model and Holland model.These results could be helpful both for studying the phonon thermal conductivity and for performing our further work.