Enhanced thermoelectric power factor of Bi2Sr2Co2Oy thin films by incorporating Au nanoparticles

Abstract c -Axis oriented Bi 2 Sr 2 Co 2 O y thin films imbedded with Au nanoparticles were prepared by pulsed laser ablation a ceramic Bi 2 Sr 2 Co 2 O y target with a small piece of Au foil overlapped. It was found that the incorporation of Au nanoparticles, about 5–15 nm in diameter, did not disrupt the c -axis orientation of the films. Fortunately, the incorporation of Au nanoparticles decreased the resistivity of Bi 2 Sr 2 Co 2 O y films while maintained the Seebeck coefficient almost unchanged, thus resulted in an enhanced power factor. Possible mechanisms were proposed to explain the results. This work demonstrated a promising approach to optimize the thermoelectric performance of layered cobaltite thin films.