Gold Catalyst-Assisted Metal Organic Chemical Vapor Deposition of Bi-Te-Ni-Cu-Au Complex Thermoelectric Materials on Anodic Aluminum Oxide Nanoporous Template

Abstract

Complex materials have unique thermal and electron transport properties. In this work, a novel catalyst-assisted metal organic chemical vapor deposition approach was employed to make Bi-Te-Ni-Cu-Au complex materials on an anodic aluminum oxide nanoporous substrate. Nickel acetate, copper nitrate, bismuth acetate, and tellurium (IV) chloride dissolved in N,N-dimethylformamide (DMF) were used as the metal sources for Ni, Bi, Cu, and Te, respectively. Hydrogen was used as the carrier gas. The anodic aluminum oxide substrate sputter-coated on a thin gold coating and was kept at 500 °C in a quartz tube in the reaction chamber. The chemical vapor deposition time was two hours. Scanning electron microscopy was used to reveal the morphology of the deposited materials. Due to metal catalyst assisted growth, the Bi-Te-Ni-Cu-Au materials were self-assembled into islands distributed fairly uniformly on the substrate. The mechanism for the morphological development of the materials was investigated. It was found that the Au nanoparticles facilitated the formation of the complex Bi-Te-Al-Ni-Cu materials. The prepared nanostructure has the highest absolute Seekbeck coefficient value of 260 µV/K, which is more than twice the value obtained from the bulk material.