Improvement in the thermoelectric properties of porous networked Al-doped ZnO nanostructured materials synthesized via an alternative interfacial reaction and low-pressure SPS processing

Abstract

n-type ZnO-based semiconducting materials are increasingly studied for thermoelectrics (TE) in the past due to their inexpensive and non-toxic nature coupled with their high Seebeck coefficient and stability at elevated...

Tailoring the thermoelectric and structural properties of Cu–Sn based thiospinel compounds [CuM1+xSn1−xS4 (M = Ti, V, Cr, Co)]

“…The presence of some surface defects and/or micro-porosity, as observed from the SEM images presented in the previous section (Figure 3c), could have also played a role in this suppressed thermal transport. 93 In addition, the intrinsically low κ in such Sn-based thiospinels can arise from the mass fluctuation effect, induced by the large molar mass of Sn (heavy element). The suppressed thermal transport combined with the enhanced electrical transport properties (PF) has helped the Cr series to manifest higher thermoelectric zT (Figure 7e) when compared to the Co and Ti series.…”

Physical Insights on the Lattice Softening Driven Mid‐Temperature Range Thermoelectrics of Ti/Zr‐Inserted SnTe—An Outlook Beyond the Horizons of Conventional Phonon Scattering and Excavation of Heikes’ Equation for Estimating Carrier Properties

“…[9][10][11][12][13][14][15][16][17][18] The thermal conductivity is known to be suppressed by nanostructuring, rattling impurities, phonon mode softening, resonant bonding, and so forth. [10,[19][20][21][22][23][24][25] The lead-free IV-VI chalcogenide semiconductor, SnTe with the same rock-salt crystal structure as PbTe and with better mechanical properties, is considered a viable eco-friendly option for thermoelectrics. [26] However, the pristine SnTe has its drawbacks with regards to its usage as a thermoelectric material such as high charge carrier concentration (≈10 21 cm -3 ) due to the intrinsic nature of SnTe to have high Sn vacancies, small bandgap often leading to bipolar conduction, and the large energy separation between the two valence band maxima (≈0.35 eV), all of which leads to a low S and high κ e , thus ultimately lower zT in pristine stochiometric SnTe.…”

“…[ 9–18 ] The thermal conductivity is known to be suppressed by nanostructuring, rattling impurities, phonon mode softening, resonant bonding, and so forth. [ 10,19–25 ]…”

“…Figure20. Thermoelectric performance of optimized Ti//Zr doped SnTe in this work is compared with other reported SnTe dopants like Ga,[79] Cu,[113] In,[59] Mg,[40] V,[50] and the Ti-Mn/Zr-Mn codoped SnTe in this work is compared with other reported SnTe codopants such as In-Se,[114] In-Mn,[27] Bi-Pb,[28] Sb-In,[112] Ca-I [65].…”

Realizing zT Values of 2.0 in Cubic GeTe

“…As a result, a high average zT of 1.5 between 400–800 K with a peak zT of 2.0 at 773 K is achieved. Such a high performance is credited to the efficacy of the doping strategies as well as the use of spark plasma sintering as the processing method, which generally result in higher zT than hot press [80–84] . Lastly, the quality factor B analysis indicates that by further optimizing the carrier concentration, the zT in this cubic GeTe can be improved to beyond 2.…”