연구홍보포털

논문 초록 (Abstract)

Flexible thermoelectric generators (f-TEGs), fabricated by the screen printing technique, have been introduced as a semi-permanent power source for wearable and flexible electronic systems. However, the output power density of the f-TEG module is still limited due to the low ZT of the screen-printed thermoelectric (TE) film. We herein report a post ionized defect engineering process that effectively contr ols ionized defects and improves the ZT value of a screen-printed te rnary TE film. It was found that post annealing in a forming gas ambie nt (4% H-2+96% Ar) can reduce the nano- and micro-bismuth oxide particl es in screen-printed n-type BiTeSe films, resulting in a bismuth rich condition and creation of bismuth antisite defects.We achieved a maximum ZT of 0.90 with the-screen-printed n-type BiTeSe thick film at-room temperature, which is-almost comparable to that of the bulk Bi2Te2.7Se0.3 and is a 2-fold increase over the same screen-pr inted film without the hydrogen ambient annealing. To demonstrate th e applicability of this approach, a f-TEG device with 72 TE pair s (p-type Bi0.5Sb1.5Te3, forming gas annealed n-type Bi2Te2.7Se0.3) was fabricated by the screen printing technique. The device gener ated a high output power of 6.32 mW cm(-2) at Delta T=25.6 degrees C . These results demonstrate the feasibility of high performance and l arge-scale f-TEG fabrication using ionized-defect engineering.