Using anodic aluminum oxide templates and electrochemical method to deposit BiSbTe-based thermoelectric nanowires

In this study, the cyclic voltammetry method was first used to find the reduced voltages and anodic peaks of Bi³⁺, Sb³⁺, and Te⁴⁺ ions as the judgments for the growth of the (Bi,Sb)_{2 - x} Te_{3 + x}-based materials. Ethylene glycol (C₂H₆O₂) was used as a solvent, and 0.3 M potassium iodide (KI) was used to improve the conductivity of the solution. Two different electrolyte formulas were first used: (a) 0.01 M Bi(NO₃)₃-5H₂O, 0.01 M SbCl₃, and 0.01 M TeCl₄ and (b) 0.015 M Bi(NO₃)₃-5H₂O, 0.005 M SbCl₃, and 0.0075 M TeCl₄. The potentiostatic deposition process was first used to find the effect of reduced voltage on the variation of compositions of the (Bi,Sb)_{2 - x}Te_{3 + x}-based materials. After finding the better reduced voltage, 0.01 M Bi(NO₃)₃-5H₂O, 0.01 M SbCl₃, and 0.01 M TeCl₄ were used as the electrolyte formula. The pulse deposition process was successfully used to control the composition of the (Bi,Sb)_{2 - x}Te_{3 + x}-based materials and grow the nanowires in anodic aluminum oxide (AAO) templates.