Abstract

Theoretical evaluation of the electrical conductivity variation in (Bi2Te3)0.25(Sb2Te3)0.75 crystallized by THM

Author(s): G.Kavei, M.A.Karami

Experimental and numerical results as presented here demonstrate the adverse effects of a Travelling HeaterMethod (THM) in (Bi2Te3)0.25(Sb2Te3)0.75 thermoelectric crystallization, onmass transport. Growthwith THMreveals that there is a considerable effect from the deflection of the solid–liquid interface, whereas the Bi2Te3 stoichiometry does change significantly. At defined length measurements of the thermoelectric crystallized ingot, electrical conductivity was carried out at intervals of defined length (6mm). A sensible gradient was observed in the reading along the ingot from a fulfilled tip to the end. To understand this variation by taking into account all practical experiences of a crystal growth,wemust conduct a numerical study because it gives vast information on a crystal growing process. Simulating the crystallization process and characterization of the ingots disclose a variation in the measured values of the thermoelectric parameters which was attributed to the deviation of Bi2Te3 concentration along the ingot.