Improvements on electrodeposited Bi 2 Te 3-y Se y films by different additives

Bismuth tellurium selenide (Bi2Te3-ySey) films have been electrochemically grown in a conventional three electrode cell. The additi on of different components to the bath, namely Sodium Lignosulfonate (SLS) and Ethylendiaminetetraacetic Acid (EDTA) an d their influence in morphology, stoichiometry, structure and Seebeck coefficient was studied in order to improve the th ermoelectric performance of Bi2Te3-ySey films. Films grown with SLS presented high crystallographic orientation and im proved morphology, while those grown in the presence of EDTA had higher concentration of bismuth. The combination of both additives gave rise to stoichiometric Bi2Te2.7Se0.3 films with denser morphology, higher orientation and higher Seebeck co efficients (60% larger) when compare with films grown without additives.