Acceptor Impurity of Copper in ZnSb Thermoelectric

• Main Authors: Shabaldin, A.A., Prokof’eva, L.V., Konstantinov, P.P., Burkov, A.T., Fedorov, M.I.
• Format: Conference Proceeding
• Language: English
• Subjects: doping mechanism; Hall coefficient; Thermoelectric; ZnSb
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2015.05.100

Hall, Seebeck coefficients and electrical conductivity of copper-doped ZnSb were studied at 300-720K for copper content in the range from 0 up to 0.6 at. %. A pronounced temperature hysteresis of the properties was observed in the heating-cooling cycles. Copper was found to be more effective acceptor at elevated temperatures. At room temperature the density of holes increases with Cu content and stabilizes at the level of about 2.5x1019 cm-3. Additional activation of the impurity begins at T ∼ 500K. The hole concentration attains the limiting value at a higher temperature. This temperature depends on the doping level: it is lower for the lower doping level. The temperature dependent doping process is related to the change in the sample microstructure and to the equilibrium defect concentration. The equilibrium defect state is achieved much slower on cooling (at lower temperatures) than on heating