In recent decades, bismuth telluride (Bi2Te3) has been in widespread use for normal-temperature thermoelectric cooling. However, commercial zone-melted bismuth telluride faces the big challenge of dramatically decreased thermoelectric properties at… Click to show full abstract
In recent decades, bismuth telluride (Bi2Te3) has been in widespread use for normal-temperature thermoelectric cooling. However, commercial zone-melted bismuth telluride faces the big challenge of dramatically decreased thermoelectric properties at higher temperature, which limits its usage at intermediate temperature. In this contribution, the thermoelectric performance of p-type bismuth telluride is enhanced via a synergistic optimization by hot deformation and copper doping. Hot deformation treatment boosts the grain growth and exhibits donor-like effects, leading to improved electronic transport properties. Meanwhile, high-density dislocations and lattice distortions induced by dynamic recrystallization aggravate the phonon-related scattering and significantly compress the lattice thermal conductivity. In addition, copper doping effectively tunes the hole concentration, and the generated point defects also reduce the lattice thermal conductivity. Consequently, a high ZTmax of 1.1 at 400 K and ZTave of...
               
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