Controlled segregation of dopant in Bridgman-grown n-type thermoelectric alloys

Abstract The segregation of the dopant as well as the main elements in the Bridgman-grown n-type thermoelectric alloy (Bi 2 Te 3 ) 90 (Sb 2 Te 3 ) 5 (Sb 2 Se 3 ) 5 was studied by using radioactive isotopes to trace the distribution of the elements, and by measuring the distribution of the electrical resistivity which corresponds to the change carrier concentration, along the grown ingot. The experimental results show the importance of controlling the ratio of the temperature gradient to the growth rate in order to obtain uniform distribution of the dopant in normal freezing grown materials.