Fabrication of 500�C Class Thermoelectric Module and Evaluation of its High Temperature Stability

Excessively Doped PbTe with Ge-Induced Nanostructures Enables High-Efficiency Thermoelectric Modules

“…29 In this study, we achieved an even higher module efficiency with newly developed nanostructured thermoelectric materials; using nanostructured Pb 0.953 Na 0.040 Ge 0.007 Te as a p-type leg and PbTe 0.9964 I 0.0036 as an n-type leg, we developed an eight-pair module with an efficiency of $8.5% for DT = 590 K. We also demonstrated an exceptionally high efficiency of $12% for a cascade Bi 2 Te 3 /nanostructured PbTe module at DT = 590 K; this efficiency is twice that reported for a cascade Bi 2 Te 3 /PbTe module using non-nanostructured PbTe ($6.1% for DT = 485 K). 44 Three-dimensional finite-element simulations predicted a 30% enhancement in the maximum conversion efficiency of our nanostructured eight-pair module, which can be achieved by improving the electrical and thermal contacts between the nanostructured legs and the Cu interconnecting electrodes, particularly at elevated temperatures.…”

“…These h max values are nearly double those reported previously for a cascaded Bi 2 Te 3 /PbTe module based on non-nanostructured PbTe (e.g., $6.1% for DT = 485 K). 44 Measured and simulated open-circuit voltage (V OC ), internal resistance (R in ), maximum power output (P max ), open-circuit heat flow (Q oc ), and maximum conversion efficiency (h max ) values. The hot-side temperature (T h ) was varied from 873 K to 573 K, while the cold-side temperature (T c ) was maintained at 283 K. The lengths of the thermoelectric materials and diffusion barriers were $3.2 and $1.1 mm, respectively.…”

Thermoelectric power generation: from new materials to devices

“…Because the ZT of PbTe-based materials has now been dramatically boosted through the new strategies discussed above [28,30,[170][171][172][173][174], recently we achieved higher η max in nanostrucuted Pb-based modules than the old PbTe modules [38,154] and diffusion barriers (figure 6a). For the new PbTe-based modules, Fe-, Ni and Nb-based alloys were investigated as diffusion barriers [38,[175][176][177][178][179]. In newly developed high-performance module, Fe and 80% Co-20% Fe were used as a diffusion barrier for p-type Pb 0.953 Ge 0.007 Na 0.040 Te and n-type PbTe 0.9964 I 0.0036 , respectively [154].…”

Screening Metal Electrodes for Thermoelectric PbTe

“…In addition, reaction and diffusion also occured at joints during device operations when directly bonding Nb foil and Ni foil to PbTe, limiting device operation time, as well as the case of NiFeMo . Thus, a diffusion barrier layer inertial to PbTe, such as Fe , and Co alloys, ,, is usually required when choosing the above-mentioned metals as electrodes. Although this kind of multiple-layer electrode structure is widely used in many thermoelectric devices, , the complicated structure increases the difficulty of device fabrication.…”

“…28 In addition, reaction and diffusion also occured at joints during device operations when directly bonding Nb foil 29 and Ni foil 30 to PbTe, limiting device operation time, as well as the case of NiFeMo. 31 Thus, a diffusion barrier layer inertial to PbTe, such as Fe 32,33 and Co alloys, 3,25,27 is usually required when choosing the above-mentioned metals as electrodes.…”