Preparation of Bi_(2-x)Sb_xTe_3 thermoelectric films by electrodeposition

摘要

Bi_(2-x)Sb_xTe_3 thermoelectric films were electrochemically deposited from the solution containing Bi~(3+), HTeO_2~+ and SbO~+. ESEM (environmental scanning electron microscope) investigations indicated that the crystalline state of Bi_(2-x)Sb_xTe_3 films transformed from equiaxed crystal to dendritic crystal with the negative shift of deposition potential. XRD and EDS were used to characterize the structure and composition of the electrodeposited films. The Seebeck coefficient and the temperature dependence of the resistance of Bi_(2-x)Sb_xTe_3 films were measured. The results showed that the composition of the film electrodeposited at -0.5 V is Bi_(0.5)Sb_(1.5)Te_3 with the largest Seebeck coefficient of 213 mu V centre dot K~(-1).