Insights into the Electrodeposition of Bi[sub 2]Te[sub 3]

Abstract

In this paper, the processes associated with the electrodeposition of bismuth telluride (Bi2Te3), a thermoelectric material, are reported along with an analysis of the composition and crystallinity of the resulting films. The electrodeposition can be described by the general reaction 3HTeO2+ + 2Bi3+ + 18e- + 9H+ → Bi2Te3 + 6H2O. Cyclic voltammetry studies of Bi, Te, and Bi/Te dissolved in 1 M HNO3 reveal two different underlying processes depending on the deposition potential. One process involves the reduction of HTeO2+ to Te0 and a subsequent interaction between reduced Te0 and Bi3+ to form Bi2Te3. A second process at more negative reduction potentials involves reduction of HTeO2+ to H2Te followed by the chemical interaction with Bi3+. Both processes result in the production of crystalline Bi2Te3 films in the potential range -0.1 < E