摘要
Bismuth telluride（Bi2Te3） based alloys, such as p-type Bi（0.5）Sb（1.5）Te3, have been leading candidates for near room temperature thermoelectric applications. In this study, Bi（0.48）Sb（1.52）Te3 bulk materials with MnSb2Se4 were prepared using high-energy ball milling and spark plasma sintering（SPS） process. The addition of MnSb2Se4 to Bi（0.48）Sb（1.52）Te3 increased the hole concentration while slightly decreasing the Seebeck coefficient, thus optimising the electrical transport properties of the bulk material. In addition, the second phases of MnSb2Se4 and Bi（0.48）Sb（1.52）Te3 were observed in the Bi（0.48）Sb（1.52）Te3 matrix. The nanoparticles in the semi-coherent second phase of MnSb2Se4 behaved as scattering centres for phonons,yielding a reduction in the lattice thermal conductivity. Substantial enhancement of the figure of merit, ZT, has been achieved for Bi（0.48）Sb（1.52）Te3 by adding an Mn（0.8）Cu（0.2）Sb2Se4（2mol%） sample, for a wide range of temperatures, with a peak value of 1.43 at 375 K, corresponding to -40% improvement over its Bi（0.48）Sb（1.52）Te3 counterpart. Such enhancement of the thermoelectric（TE） performance of p-type Bi2Te3 based materials is believed to be advantageous for practical applications.
Bismuth telluride（Bi2Te3） based alloys, such as p-type Bi（0.5）Sb（1.5）Te3, have been leading candidates for near room temperature thermoelectric applications. In this study, Bi（0.48）Sb（1.52）Te3 bulk materials with MnSb2Se4 were prepared using high-energy ball milling and spark plasma sintering（SPS） process. The addition of MnSb2Se4 to Bi（0.48）Sb（1.52）Te3 increased the hole concentration while slightly decreasing the Seebeck coefficient, thus optimising the electrical transport properties of the bulk material. In addition, the second phases of MnSb2Se4 and Bi（0.48）Sb（1.52）Te3 were observed in the Bi（0.48）Sb（1.52）Te3 matrix. The nanoparticles in the semi-coherent second phase of MnSb2Se4 behaved as scattering centres for phonons,yielding a reduction in the lattice thermal conductivity. Substantial enhancement of the figure of merit, ZT, has been achieved for Bi（0.48）Sb（1.52）Te3 by adding an Mn（0.8）Cu（0.2）Sb2Se4（2mol%） sample, for a wide range of temperatures, with a peak value of 1.43 at 375 K, corresponding to -40% improvement over its Bi（0.48）Sb（1.52）Te3 counterpart. Such enhancement of the thermoelectric（TE） performance of p-type Bi2Te3 based materials is believed to be advantageous for practical applications.
基金
supported by the National Natural Science Foundation of China(Grant Nos.51472052 and Y6J1421A41)
