Influence of pulsed electrodeposition on stoichiometry and thermoelectric properties of bismuth telluride films

Bismuth telluride films were synthesized using pulsed electrodeposition, Synthesis of films from electrolytes with different [Bi]/[Te] ratios evidenced that an increase of bismuth concentration in the electrolyte leads to a decrease of the tellurium percentage in the film. A more important study with the ratio [Bi]/[Te] = 2 was carried out in order to correlate pulse parameters and film compostions. A crystallographic study underlined a variation of grains orientation following to the stichiometry. The comparision of thermoelectric properties of pulsed and direct electrodeposited films showed that pulsed electrodeposition improves the morphology and decreases the electrical resistivity of films. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim