Incorporation of Au nanoparticles into thermoelectric mesoporous ZnO using a reverse triblock copolymer to enhance electrical conductivity

Abstract

Since the thermoelectric properties are proportional to the electrical conductivity and inversely proportional to the thermal conductivity, independent control of thermal conductivity and electrical conductivity is essential. Therefore, in this study, mesoporous structure was applied to decrease thermal conductivity. And, Au NPs were incorporated to increase the electrical conductivity. Reverse triblock copolymer and cosolvent system were introduced for uniform dispersion of Au NPs. The collapse of the pore structure was minimized due to the uniform dispersion of Au NPs and the porosity increased by 10% from 20% to 30% when compared with pristine ZnO thin films. A mesoporous ZnO composite thin film containing 1 at.% Au NPs exhibited an electrical conductivity that was five times greater than that of a pristine mesoporous ZnO thin film. In addition, the power factor increased by about 3.5 times, from 9.53 ± 1.50 μW/mK2 to 32.72 ± 5.16 μW/mK2 at 503 K.