Influence mechanism of nano-TiO2 dispersion on thermoelectric properties of BiCuSeO

作者：Feng, Bo^*; Liu, Yi; Tang, Yong

来源：Journal of Materials Science: Materials in Electronics , 2022, 33(20): 16396-16405.

DOI：10.1007/s10854-022-08531-z

• PHONON-SCATTERING
• ANATASE TIO2
• BAND-GAP
• PERFORMANCE
• POWER
• CONDUCTIVITY
• EFFICIENCY
• INTERFACE
• POLYMERS

The influence mechanism of Nano-TiO2 on the electrical and thermal transporting properties of BiCuSeO ceramics has been investigated. BiCuSeO matrix powders and nano-TiO2 powders were mixed by high-energy mechanical alloying, and then sintered by spark plasma method. The results of micromorphology tests indicated that the nano-TiO2 particles were distributed on the surface and interior of the matrix. Due to the low electrical conductivity (sigma) of TiO2 , the sigma of the dispersed sample decreased slightly after the compositing. For the energy filtering effect and the decrease of carrier concentration caused by the nano-TiO2 particles, the Seebeck coefficient increases in the whole temperature zone from room temperature to 873 K. For that the average free path of phonons decreased due to the nano dispersed particles, the thermal conductivity decreased correspondingly. Through the dispersion of nano-TiO2, the electron/phonon transporting of BiCuSeO has reached a better balance, and the thermoelectric properties improved significantly with the largest ZT of similar to 1.204 at 873 K.