Large enhancement of thermoelectric performance of CuInTe 2 via a synergistic strategy of point defects and microstructure engineering

Copper chalcogenide thermoelectric materials

“…In addition, the nanostructuring approach was also employed [133,134]. The enhanced thermoelectric performance can be attributed to the phonon scattering introduced by crystal defects and the increased density of states near the Fermi level, such as (CuInTe 2 ) 0.99 (ZnTe) 0.01 composited with 0.1 wt% TiO 2 nanofiber (zT~1.47 at 823 K) [135], CuInTe 2 composited ZnO (zT~1.61 at 823 K) [34].…”

Progressive Regulation of Electrical and Thermal Transport Properties to High‐Performance CuInTe2 Thermoelectric Materials

“…where is the reduced Plank constant, k B is the Boltzmann constant, θ is the Debye temperature, υ is the phonon velocity of CuInTe 2 compound, z is the usual dimensionless variable ω/k B T , and τ is the phonon relaxation time, which can be expressed as [ 24 ] τ τ τ τ τ γ ω ν θ π ω π π ω ( ) …”

“…However, its widespread application is still restricted by the low conversion effi ciency of thermoelectric materials, [ 1 ] which is usually determined by the dimensionless fi gure of merit, ZT = S 2 σT / κ = S 2 σT /( κ e + κ l ), where S is the Seebeck coeffi cient; σ is the electrical conductivity; T is the absolute temperature; κ , κ e , and κ l are the total, electronic, and lattice thermal conductivities, respectively. [ 2 ] previous TiO 2 added sample, [ 24 ] thus reducing its output power. Therefore, how to realize a concurrent improvement of both the electrical and thermal transport properties is a tough challenge to be conquered.…”

“…Moreover, in situ oxidation was employed to introduce dispersive In 2 O 3 nanoparticles by adding ZnO nanopowders, by this way, the thermal conductivity was lowered signifi cantly, and more importantly, the electrical transport properties were also improved originated from the formation of Zn In − point defects, thus avoiding the reduction of electrical properties as observed in other methods. [ 23,24 ] Ultimately, by incorporating the anion substitution and in situ oxidation, a semiconductor to metal behavior transformation was observed, and a high power factor and a low thermal conductivity were integrated in this compound, which lead to an unprecedented thermoelectric performance in the CuInTe 2 based TE materials. Figure 1 shows the X-ray diffraction (XRD) patterns of the CuInTe 2 and CuInTe 1− x M x (M = P, Sb; x = 0.01, 0.02) samples.…”

High Thermoelectric Performance in Polycrystalline SnSe Via Dual‐Doping with Ag/Na and Nanostructuring With Ag8SnSe6

“…They include enhancement of the electrical conductivity by enhancing the carrier concentration with chemical doping and carrier injection, enhancement of the Seebeck coefficient though band engineering (band convergence, resonant level, electronic density of states distortion, Fermi level pinning) and carrier engineering (minority carrier blocking, energy barrier filtering) . On the other hand, the thermal conductivity can be reduced through tailoring the independent κ L through introducing phonon scattering by atomic‐scale point defects, nanoscale dislocations, stacking faults and particles, mesoscale grains and boundaries, as well as multiscale hierarchical architectures …”