Electrodeposition of p-Type SbxTey Thermoelectric Films

Abstract

Thermoelectric Sb (x) Te (y) films were potentiostatically electrodeposited in aqueous nitric acid electrolyte solutions containing different concentrations of TeO2. Stoichiometric Sb (x) Te (y) films were obtained by applying a voltage of -0.15 V versus saturated calomel electrode (SCE) using a solution consisting of 2.4 mM TeO2, 0.8 mM Sb2O3, 33 mM tartaric acid, and 1 M HNO3. The nearly stoichiometric Sb2Te3 films had a rhombohedral structure, R (3) over barm with a preferred orientation along the (015) direction. The films had hole concentration of 5.8 x 10(18)/cm(3) and exhibited mobility of 54.8 cm(2)/Vs. A more negative potential resulted in higher Sb content in the deposited Sb (x) Te (y) films. Furthermore, it was observed that the hole concentration and mobility decreased with increasingly negative deposition potential, and eventually showed insulating properties, possibly due to increased defect formation. The absolute value of the Seebeck coefficient of the as-deposited Sb2Te3 thin film at room temperature was 118 mu V/K.