Interfacial bonding enhances thermoelectric cooling in 3D-printed materials

Thermoelectric coolers (TECs) are pivotal in modern heat management but face limitations in efficiency and manufacturing scalability. We address these challenges by using an extrusion-based 3D printing technique to fabricate high-performance thermoelectric materials. Our ink formulations ensure the integrity of the 3D-printed structure and effective particle bonding during sintering, achieving record-high figure of merit (zT) values of 1.42 for p-type bismuth antimony telluride [(Bi,Sb)₂Te₃] and 1.3 for n-type silver selenide (Ag₂Se) materials at room temperature. The resulting TEC demonstrates a cooling temperature gradient of 50°C in air. Moreover, this scalable and cost-effective method circumvents energy-intensive and time-consuming steps, such as ingot preparation and subsequently machining processes, offering a transformative solution for thermoelectric device production and heralding a new era of efficient and sustainable thermoelectric technologies.