Effect of Chromium Doping on the Thermoelectric Properties of Bi2Te3: CrxBi2Te3 and CrxBi2−xTe3

The thermoelectric (TE) properties of Bi2Te3 compounds intercalated and substituted with Cr, namely Cr x Bi2Te3 and Cr x Bi2−x Te3, respectively, have been investigated to study the influence of chromium on the TE properties of Bi2Te3. The Seebeck coefficients were found to be positive for all the samples in the temperature range between 300 K and 550 K. Although no effective enhancement of the Seebeck coefficient was observed, doping with Cr by means of either substitution or intercalation clearly not only improved the electrical conductivity but also lowered the thermal conductivity of Bi2Te3. As a result of the improvement, the figure of merit ZT is increased up to 0.8 and 0.65 at 300 K for 1% intercalated and 1% substituted Bi2Te3, respectively.