SIMULATION ANALYSIS FOR PHONON CONDUCTIVITY OF GERMANIUM

摘要

The thermal conductivity of non metallic solids, doped with isotopic impurities hasrnbeen the subject of great interest in the past because of their wide applications in thernsemiconductor device industry. We analyse the thermal conductivity of intrinsicrnsemiconductors, the thermal transport behaviour of which is similar to that of anrninsulator with heat conduction due to phonons or lattice waves . To estimate phononrnconductivity of these solids based on the Callaway's phenomenological model, workersrnhave directly assumed that the relaxation rates due to isotopic impurities (τ~1D～Aω~4)rnand anharmonic interactions (τ~1A=Bω~2T~3) are independent of each other. In thernpresent analysis, we have discussed the inter-dependence of these relaxation rates inrnthe form of a cross term (Γ~(AD)) and its role in estimation of the phonon conductivity.rnThe present analysis is more rigorous and involve less approximation as compared withrnother models. Therefore, simulation analysis has been applied and good agreementrnbetween theory and experiment is achieved in the temperature range 2 to 100 oK.rnSimulation analysis also enables us to observe the behavour of the other parameters takenrnin the proposed model.