Work

Effect of microstructure on the thermoelectric properties of CSD-grown Bi2Sr2Co2Oythin films

Year: 2013

Type: article

Abstract: Three Bi 2 Sr 2 Co 2 O y thin films with different microstructures have been prepared by chemical solution deposition on LaAlO 3 (001) through varying the annealing temperature. With the decrease in the annealing temperature, both the size and c-axis alignment degree of grains in the film decrease as well, leading to an increase in the film resistivity. In addition, the decrease in the annealing temperature also results in a slight increase in the Seebeck coefficient due to the enhanced energy filtering effect of the small-grain film. The nanostructured Bi 2 Sr 2 Co 2 O y film with an average grain size of about 100 nm shows a power factor comparable to that of films with larger grains. Since the thermal conductivity of the nanostructured films can be depressed due to the enhanced phonon scattering by grain boundary, a higher figure of merit is expected in Bi 2 Sr 2 Co 2 O y thin film with grains in nanometer size.

Source: Chinese Physics B

DOI: 10.1088/1674-1056/22/3/037302