This research investigates the combination of electrochemical deposition and postdeposition vapor annealing as a method for the fabrication of Bi2Te3 layers. The galvanostatic deposition of Bi2Te3 thin films is characterized as a function of electrolyte composition and deposition-current density. Material with near-stoichiometric composition can be synthesized from electrolytes containing 20 mM Te and 30 mM Bi ions and a deposition-current density of 3.75 mA/cm2. All deposited samples show n-type behavior with Seebeck coefficients around −55 μV/K. An equilibrium annealing process in Te atmosphere is used to readjust the composition of the material after the deposition, consistently leading to tellurium-rich Bi2Te3 with a Te content of 60.4 ± 0.4 at%. At a temperature of 250 °C, an annealing duration of 60 h is sufficient for the material properties to reach a steady state, with a Seebeck coefficient of −130 μV/K.
