Electrodeposition and morphology analysis of Bi–Te thermoelectric alloy nanoparticles on copper substrate

Nanoscale Bi–Te particles with thermoelectric properties on copper substrate were investigated. The substrate was prepared by electroplating copper layer on a copper zinc alloy plate in a copper sulfate solution. Electrodeposition of the Bi–Te alloy particles was then performed in a nitrate bath. The electrolyte is composed of 0.05 M bismuth nitrate and 0.01 M tellurium dioxide dissolved in 2.0 M HNO3. Cyclic voltammetry and quartz microbalance tests associated with the electrodeposition process were conducted to show the mechanism and kinetics of the deposition. The morphology and compositional analysis of Bi–Te was obtained using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) respectively. The morphology analysis suggested that nanoscale Bi–Te particles were obtained and the EDS results indicated that the surface of the copper substrate contained Cu2O. The atomic ratio 1:1 for Bi:Te in the alloy, which is equivalent to the weight percentage of Bi:Te = 62%:38% was confirmed from the data obtained.