Efforts Toward the Fabrication of Thermoelectric Cooling Module Based on N‐Type and P‐Type PbTe Ingots

The rapid advancement of Internet of Things (IoT) technology and AI microchips has increased the demand for efficient and cost‐effective cooling solutions. However, traditional Bi2Te3‐based thermoelectric modules face the challenge of low abundance tellurium (Te). Although Te‐free modules using MgAgSb have been explored, they still suffer from a low price‐to‐performance ratio. To address these issues, this study investigates the development of alternative thermoelectric materials that are both cost‐effective and Te free. In this work, the potential of cost‐effective Te‐free alternatives is explored for thermoelectric applications by developing a high‐performance module composed of amorphous carbon‐modulated Mg3(Bi,Sb)2 and electron‐poor CdSb. The modules of CdSb/Bi2Te3 and CdSb/Mg3(Bi,Sb)2 demonstrate superior refrigeration performance, achieving a maximum temperature difference (ΔTmax) of 49.2 and 46 K, respectively. Notably, the material cost of CdSb/Mg3(Bi,Sb)2 module is only 5.5% of Te‐free modules built on MgAgSb, highlighting a significant economic advantage. This work provides a viable, ultralow‐cost approach to meet general refrigeration needs, thereby enhancing the practical value and application potential of thermoelectric materials.

Amorphous Carbon‐Modulated Mg₃(Bi,Sb)₂ and Electron‐Poor CdSb for Ultralow‐Cost Te‐Free Refrigeration Modules

Xu,

Al‐Maythalony,

et al. 2024

Stepwise Optimization of Thermoelectric Performance in n‐Type SnS

Hu,

Bai,

Wen

et al. 2024

Tin sulfide (SnS) has been developed as an earth‐abundant and eco‐friendly compound that exhibits promising thermoelectric (TE) performance. While significant achievements are achieved in p‐type SnS, the development of its n‐type counterpart remains at a nascent stage, making it rather essential for developing n‐type SnS to ensure good compatibility in SnS‐based TE devices. In this study, Br is selected as the aliovalent dopant for realizing n‐type transport in SnS. Subsequently, isoelectronic Se alloying and vacancy compensation are utilized to further promote the TE performance for n‐type SnS. Se alloying can effectively narrow the bandgap of SnS for enhancing carrier concentration and diminishing thermal conductivity by strain and mass field fluctuations, while the excess Sn further compensates intrinsic Sn vacancies, thus optimizing carrier concentration and mobility simultaneously. These results are well verified by microstructure characterization and defect formation energy calculations. Consequently, the maximum ZT value of ≈0.7 and quality factor B of ≈1.02 at 823 K can be obtained after stepwise optimization, which is currently the highest value for n‐type SnS thermoelectrics. This study presents a significant progress for n‐type SnS and lays an important foundation for constructing all‐SnS‐based TE devices.

Prefer‐Oriented Ag₂Se Crystal for High‐Performance Thermoelectric Cooling

Jiang,

Lin,

Cheng

et al. 2024

Ag2Se‐based materials with promising room‐temperature thermoelectric performance have been known for decades. However, thermoelectric cooling devices based on bulk Ag2Se have seldom been reported, mainly due to the phase transition ≈400 K poses a grand challenge for leg design and module integration. Herein, Ag2Se crystals with the preferred orientation have been prepared. A high carrier mobility of ≈1846 cm2 V−1 s−1 and a power factor of ≈31.2 µW cm−1 K−2 at room temperature has been realized, and results in a zT of ≈0.95 at 300 K. Importantly, by applying Ag as the contact layer, the Ag/Ag2Se/Ag joint has been prepared by one‐step sintering. By maintaining the pressure of ≈10 MPa after sintering and during the reflow soldering, the deleterious effect of the large thermal expansion can be alleviated. The contact resistance of the Ag/Ag2Se interface is as low as ≈2.9 µΩ cm2, indicating negligible electrical parasitic loss. The thermoelectric device with 7 pairs of Ag2Se and (Bi, Sb)2Te3 has been fabricated and it can achieve a maximum cooling power of ≈2.90 W and a cooling temperature difference of ≈70.4 K at the hot‐side temperature of 350 K, demonstrating the great potential of Ag2Se for cooling applications.