| Summary: | 碩士 === 國立中正大學 === 化學工程研究所 === 107 === In this study, a self-made lateral hot pressing system was used for current-assisted hot pressing to fabricate a lateral thermoelectric element. The material used for this component is p-type Bi0.5Sb1.5Te3, which was first ground to powder of 5 μm in size. The powder was placed into slurry and scraped onto nickel to prepare a film of 100 μm.. Subsequently, the thermoelectric film is alternately stacked at a specific angle in a self-made lateral hot pressing system, and then current-assisted hot pressing is performed to produce a lateral thermoelectric element. During the hot pressing process, it is found that thermoelectric film and ni form a joint compound which is called an intermetallic compound (IMC). The formation of this compound increased the contact resistance, affecting the performance of the lateral thermoelectric device.The results show that the maximum output power of the lateral thermoelectric device is 11.62 nW under the temperature of 340℃ and 134 MPa for 30min, and the output power is obviously lower than the theoretical value of 178.19 nW. Therefore, this study’s target is to fulfill the theoretical value through the current-assisted hot pressing. Because of electric driving force and the Jouel heating effect, the bonding between NiTe/Ni will achieve better and effectively eliminate the defects of the thermoelectric material at an appropriate time. Accroding to the results the hot pressing was carrying out for 10 minutes, and subsequently current-assisted hot pressing was applying 5 minutes at current density of 800 A/cm2 , so that the resistance of the device could be greatly reduced and the open circuit voltage was increased. The maximum output power value could reach to 75.73 nW, Hence, the current assisted hot pressing treatment is effective to improve the thermoelectric properties of the lateral thermoelectric device.
|
|---|
