Fig. 5.

Electrical and thermal transport of p–n segmented TE fiber in TET. a Design structure of TET and p–n junction alternate between the hot and the cold sides. The illustration (left) is the TET’s cross section, confirming vertical arrangement of n-segment and p-segment in TE fibers. b Thermal diagram during heat transport in the prepared woven TET. Note: TR on behalf of thermal resistance (TR_c1 and TR_c2 are the thermal resistances of the cold and hot sides, respectively, and TR_ANFs, TR _textile and TR_TE are thermal resistance of the hollow ANFs/MMT fiber layer, textile substrate and p–n segmented TE fiber, respectively). Q represents the generated heat inputs (Q_{P, h} and Q_{J, h} are input thermal produced via Peltier effect and Joule heating at the hot sides, respectively; Q_{P, c} and Q_{J, c} are input thermal produced via Peltier effect and Joule heating at the cold sides, respectively). c Circuit diagram of TET during electrical transmission in TET. Note: R and r are external and internal resistances of TET, respectively. d The temperature distribution of the TET by finite element analysis. The temperature distribution of the aramid fabric substrate e and p–n segmented TE fiber f. g Optical image of the resultant TET through stitching the alternating p–n segmented TE fiber into a flexible aramid fabric (5 cm × 4.5 cm), exhibiting outstanding flexibility, including bending and folding. h Output voltage curve of TET at the different heating temperatures ranging from 100 to 400 °C. i Open-circuit voltage and current as functions of temperature. j Maximum power density of as-prepared TET at various temperatures. k Output voltage curve of TET concerning temperature difference