Fabrication, Characterization Of Film Thermoelectric Materials And Development Of Thermoelectric Performance Measurement System

Substance converting heat into electric energy under certain range of temperature is called thermoelectric material, of which converting efficiency is mainly determined by its own intrinsic properties and evaluated by ZT of dimensionless factor. For many years researchers make great efforts to prepare thermoelectric materials with high value of ZT. The up-to-moment developments show that the value of ZT can be improved greatly by reducing dimensions of the materials. Now electrodeposited thermoelectric film arouses the interest of the researchers, not only for the fitting of micro-electronics, but also the guidance to the electrodepositing nanowire. This experiment focus on the fabrication processes of N-type Bi2-xTe3+x and P-type (Bi1-xSbx)2Te3 films, which provided a new exploring way to improve the thermoelectric performance of the BiTe-base materials. We also developed a new thermoelectric performance measurement system. The Bi-Te co-deposition process of N-type film and influence of the deposited voltage have been studied. The film's composition, morphology and structure have been also investigated by ESEM, XRD, and EDS. The Seebeck coefficient measurement analysis indicated that Bi2-xTe3+x film have N-type semiconductor characteristic. The Bi-Te-Sb co-deposition process of P-type film have been studied and influence of the deposited voltage, temperature have been also studied to find the optimal deposited condition. The film's composition, morphology and structure have been also investigated by ESEM, XRD, XPS and EDS. The analysis indicated that the film composition had been close to optimal composition and the thermoelectric performance increased greatly. Because the traditional thermoelectric performance measurement system is not fit for nanowire arrays, we developed a new measurement system, which has been successful measured the nanowire arrays,the bulk and film thermoelectric materials. Mathematics calculation indicated that the system had high relative precision and exactitude, which can satisfy the demand of our research.