抄録
In order to develop a new process of forming a carrier concentration gradient in PbTe only by heat treatment, the effect of heat treatment temperature on a carrier concentration n of the p-type PbTe has been investigated. The stoichiometric PbTe was p-type with a n of 1.0×1024/m3. Vacuum thermal exposure with Te-rich PbTe at 900K for 1h increased the n of the stoichiometric PbTe to 5.1×1024/m3. The thermally exposed stoichiometric PbTe was heat treated at temperatures from 400 to 900K for 24h. The n decreased with increasing heat treatment temperature between 300 and 500K, while increased with temperature between 500 and 900K. A minimum n was measured at 500K. The thermally exposed PbTe 19mm long was also heat treated under a temperature gradient of 340-900K for 24h. The n changed continuously with a minimum at 500K. The graded n was successfully formed in the p-type PbTe by temperature-graded heat treatment.
