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

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 Mg-3(Bi,Sb)(2) and electron-poor CdSb. The modules of CdSb/Bi2Te3 and CdSb/Mg-3(Bi,Sb)(2) demonstrate superior refrigeration performance, achieving a maximum temperature difference (Delta T-max) of 49.2 and 46 K, respectively. Notably, the material cost of CdSb/Mg-3(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.