Electrochemical deposition of Bi2Te3 for thermoelectric microdevices

The electrolyses of solutions of bismuth oxide and tellurium oxide in nitric acid with molar ratios of Bi:Te=3:3-4:3 lead to cathodic deposits of films of bismuth telluride (Bi2Te3), an n-type semiconductor. Current densities of 2-5 mA/cm(2) were applied. Voltammetric investigations showed that Bi2Te3 deposition occurred at potentials more negative than -0.125 V (Ag/AgCl, 3 M KCl). The deposit was identified as bismuth telluride (gamma-phase) by X-ray analysis. Hall-effect measurements verified the n-type semiconducting behaviour. The films can be deposited in microstructures for thermoelectric microdevices like thermoelectric batteries or thermoelectric sensors.