Extremely low thermal conductivity of β−Ga2O3 with porous structure.

Autor: Wu, H. J., Ning, S. T., Qi, N., Ren, F., Chen, Z. Q., Su, X. L., Tang, X. F.
Předmět:
Zdroj: Journal of Applied Physics; 11/21/2021, Vol. 130 Issue 19, p1-9, 9p
Abstrakt: Due to the ultrawide bandgap (4.9 eV), high carrier mobility (300 cm 2 V − 1 s − 1 ), and high thermal stability, β − Ga 2 O 3 can be a potential candidate for high-temperature thermoelectric materials. However, the intrinsically high thermal conductivity may hinder its application for thermoelectric conversion. In this work, porous β − Ga 2 O 3 was prepared by the solvothermal method together with spark plasma sintering technology. Positron lifetime measurement and N 2 adsorption confirm the introduction of pores by adding sucrose in the sample preparation. The sucrose-derived β − Ga 2 O 3 sintered at a relatively low temperature of 600 ° C remains highly porous, which results in an extremely low thermal conductivity of 0.45 W m − 1 K − 1 at room temperature, and it further decreases to 0.29 W m − 1 K − 1 at 600 ° C. This is the lowest thermal conductivity for β − Ga 2 O 3 reported so far. Our work provides an avenue to reduce the thermal conductivity for β − Ga 2 O 3 and is believed to be widely applicable to many other thermoelectric materials. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index