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

Abstract 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 (ΔT_max) 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.