A boost of thermoelectric generation performance for polycrystalline InTe by texture modulation

The new rising binary InTe displays advantageously high electronic conductivity and low thermal conductivity along the [110] direction, providing a high potential of texture modulation for thermoelectric performance improvement. In this work, coarse crystalline InTe material with a high degree of texture along the [110] direction was realized by the oriented crystal hot-deformation method. The coarse grains with high texture not only maintain the preferred orientation of the zone-melting crystal as far as possible, but also greatly depress the grain boundary scattering, thus leading to the highest room temperature power factor of 8.7 mu W cm(-1) K-1 and a high average figure of merit of 0.71 in the range of 300-623 K. Furthermore, the polycrystalline characteristic with refined grains also promotes the mechanical properties. As a result, an 8-couple thermoelectric generator module consisting of p-type InTe and commercial n-type Bi2Te2.7Se0.3 legs was successfully integrated and a high conversion efficiency of similar to 5.0% under the temperature difference of 290 K was achieved, which is comparable to traditional Bi2Te3 based modules. This work not only demonstrates the potential of InTe as a power generator near room temperature, but also provides one more typical example of a texture modulation strategy beyond the traditional Bi2Te3 thermoelectrics.

Automated summary

An oriented crystal hot-deformation method was used to realize coarse crystalline InTe material with high texture along the [110] direction, exhibiting advantageous properties for thermoelectric performance improvement. The resulting high texture grains not only maintained the preferred orientation of the zone-melting crystal but also suppressed grain boundary scattering, leading to high power factor and figure of merit values. Integrating p-type InTe and commercial n-type Bi2Te2.7Se0.3 legs, an 8-couple thermoelectric generator module achieved a high conversion efficiency comparable to traditional Bi2Te3 based modules.