Improvement of Bismuth Telluride electrodeposited films by the addition of Sodium Lignosulfonate

In this work we report the improvement on the electrodeposition of Bi ₂Te₃ films with the c-axis parallel to the surface of the substrate. This has been done with the addition of a surfactant agent (sodium lignosulfonate) to the electrochemical bath. A thorough study of the electrodeposition parameters and the material composition, morphology, crystallographic orientation and transport properties was performed. High quality films oriented along the (1 1 0) plane and with a dense morphology were obtained, showing an improved Seebeck coefficient up to 33% bigger than previously reported values. The differences in the morphology due to the presence of the surfactant have been further analyzed studying the shape of films grown from discrete nucleation sites.