文摘
A post ionized defect engineering process for improving ZT value of the screen-printed BiTeSe thick film is proposed. A post annealing in a forming gas ambient (4% H2 + 96% Ar) can reduce the nano- and micro-bismuth oxide particles in screen-printed BiTeSe films, resulting in a bismuth rich condition and creation of bismuthantisite defects. A maximum ZT of 0.90 with the screen-printed BiTeSe film at room temperature, which isalmost comparable to that of the bulk Bi2Te2.7Se0.3 and is a 2-fold increase over the same screen-printed film without the hydrogen ambient annealing. A f-TEG device with 72 TE pairs (p-type Bi0.5Sb1.5Te3, forming gas annealed n-type Bi2Te2.7Se0.3) generatesa high output power of 6.32 mWcm-2 at ΔT = 25.6 °C.