1 research outputs found
Promoted Na Solubility and Modified Band Structure for Achieving Exceptional Average <i>ZT</i> by Extra Mn Doping in PbTe
Na doping strategy provides an effective avenue to upgrade
the
thermoelectric performance of PbTe-based materials by optimizing electrical
properties. However, the limited solubility of Na inherently restricts
the efficiency of doping, resulting in a relatively low average ZT, which poses challenges for the development and application
of subsequent devices. Herein, to address this issue, the introduced
spontaneous Pb vacancies and additional Mn doping synergistically
promote Na solubility with a further modified valence band structure.
Furthermore, the induced massive point defects and multiscale microstructure
greatly strengthen the scattering of phonons over a wide frequency
range, leading to a remarkable ultralow lattice thermal conductivity
of ∼0.42 W m–1 K–1. As
a result, benefiting from the significantly enhanced Seebeck coefficient
and superior thermal transports, a high peak ZT of
∼2.1 at 773 K and an excellent average ZT of
∼1.4 between 303 and 823 K are simultaneously achieved in Pb0.93Na0.04Mn0.02Te. This work proposes
a simple and constructive method to obtain high-performance PbTe-based
materials and is promising for the development of thermoelectric power
generation devices