1 research outputs found
Ga-Doping-Induced Carrier Tuning and Multiphase Engineering in n‑type PbTe with Enhanced Thermoelectric Performance
P-type
lead telluride (PbTe) emerged as a promising thermoelectric material
for intermediate-temperature waste-heat-energy harvesting. However,
n-type PbTe still confronted with a considerable challenge owing to
its relatively low figure of merit <i>ZT</i> and conversion
efficiency η, limiting widespread thermoelectric applications.
Here, we report that Ga-doping in n-type PbTe can optimize carrier
concentration and thus improve the power factor. Moreover, further
experimental and theoretical evidence reveals that Ga-doping-induced
multiphase structures with nano- to micrometer size can simultaneously
modulate phonon transport, leading to dramatic reduction of lattice
thermal conductivity. As a consequence, a tremendous enhancement of <i>ZT</i> value at 823 K reaches ∼1.3 for n-type Pb<sub>0.97</sub>Ga<sub>0.03</sub>Te. In particular, in a wide temperature
range from 323 to 823 K, the average <i>ZT</i><sub>ave</sub> value of ∼0.9 and the calculated conversion efficiency η
of ∼13% are achieved by Ga doping. The present findings demonstrate
the great potential in Ga-doped PbTe thermoelectric materials through
a synergetic carrier tuning and multiphase engineering strategy