Formation of Bismuth Nanocrystals in Bi2O3 Thin Films Grown at 300 K by Pulsed Laser Deposition for Thermoelectric Applications

Abstract

Bismuth nanocrystals were embedded in amorphous Bi2O3 thin films grown under a nitrogen atmosphere at room temperature using pulsed laser deposition. As-grown Bi2O3-Bi thin films showed a high electrical conductivity of approximately 769 S/cm at 320K, and the samples annealed in two steps at 200 and 300 degrees C consisted of amorphous Bi2O3, bismuth nanocrystals in the crystallized beta-Bi2O3 phase. The mixture phase of the bismuth nanocrystals and beta-Bi2O3 enhanced the thermoelectric properties at room temperature. Samples annealed in two steps at 200 and 300 degrees C showed an electrical conductivity of 833 S/cm, a Seebeck coefficient of -110 mu V/K, a power factor of about 1.05 x 10(-3) W/K(2)m. Formation of the bismuth nanocrystals in Bi2O3 thin films at low temperature made thermoelectric applications possible.