Robust Bi2(Te,Se)3 Thermoelectrics From Large Shrinkage Ratio Extrusion Drives Advanced Peltier Microcooler and Power Generator

Abstract The “Barrel Effect” of n ‐type Bi 2 Te 3 materials have always been the biggest obstacle to expanding thermoelectric commercial applications. This work develops an industrial‐scale large shrinkage ratio extrusion method that synchronously coordinates appropriate texturing and modifies atomic defects, as well as micro and nanostructures, prompting simultaneous gains in rods with a diameter of 30 mm increases to ≈1.20 at 325 kelvin, with flexural and compressive strengths significantly improve to 77.7 and 192.4 MPa, respectively. Successfully fabricated Peltier microcoolers (1 × 3 mm 2 cross‐section) exhibit a competitive maximum cooling temperature difference of 90.6 kelvin at a hot‐side temperature of 348 kelvin. A designed and integrated 17‐by‐17 power generator demonstrates a high conversion efficiency of 7% under a 200‐kelvin temperature gradient and highlights operational stability. These achievements hold great potential for advancing applications in compact solid‐state cooling and low‐grade waste heat recovery.