Electrodeposition of bismuth telluride (Bi2Te3) in an acidic medium with Arabic gum by galvanostatic polarization has been investigated. Simultaneous in situ spectroscopic ellipsometry and gravimetric measurements have been performed to study the morphological evolution of the compound. A progressive covering stage was demonstrated and revealed that a 40 nm thick film has already acquired morphological and optical behavior similar to that of thicker films. The optical thickness and electrochemical quartz crystal microbalance (EQCM) mass are coherent with a density of 7.06. Combined gravimetric and coulometric data confirm the formation of Bi2Te3 by determining the ratio m/z. (c) 2007 Elsevier Ltd. All rights reserved.