Work

Novel Thermal Diffusion Temperature Engineering Leading to High Thermoelectric Performance in Bi 2 Te 3 ‐Based Flexible Thin‐Films

Year: 2021

Type: article

Abstract: Flexible Bi 2 Te 3 ‐based thermoelectric devices can function as power generators for powering wearable electronics or chip‐sensors for internet‐of‐things. However, the unsatisfied performance of n‐type Bi 2 Te 3 flexible thin films significantly limits their wide application. In this study, a novel thermal diffusion method is employed to fabricate n‐type Te‐embedded Bi 2 Te 3 flexible thin films on flexible polyimide substrates, where Te embeddings can be achieved by tuning the thermal diffusion temperature and correspondingly result in an energy filtering effect at the Bi 2 Te 3 /Te interfaces. The energy filtering effect can lead to a high Seebeck coefficient ≈160 µV K −1 as well as high carrier mobility of ≈200 cm 2 V −1 s −1 at room‐temperature. Consequently, an ultrahigh room‐temperature power factor of 14.65 µW cm −1 K −2 can be observed in the Te‐embedded Bi 2 Te 3 flexible thin films prepared at the diffusion temperature of 623 K. A thermoelectric sensor is also assembled through integrating the n‐type Bi 2 Te 3 flexible thin films with p‐type Sb 2 Te 3 counterparts, which can fast reflect finger‐touch status and demonstrate the applicability of as‐prepared Te‐embedded Bi 2 Te 3 flexible thin films. This study indicates that the thermal diffusion method is an effective way to fabricate high‐performance and applicable flexible Te‐embedded Bi 2 Te 3 ‐based thin films.

Source: Advanced Science

DOI: 10.1002/advs.202103547