Laser co-ablation of bismuth antimony telluride and diamond-like carbon nanocomposites for enhanced thermoelectric performance

Abstract

A novel design of thermoelectric hetero-nanocomposite films comprising well-aligned oriented (Bi,Sb)₂Te₃ (BST) nanocrystals and randomly dispersed diamond-like carbon (DLC) clusters has been realized for the first time using dual-beam pulsed laser co-deposition on SiO₂ insulated Si substrates. The simultaneously deposited DLC additives were found not only to successfully prevent the thermally induced rapid growth of BST for having consistent nanostructures across the whole BST:DLC film, but also to effectively reduce the thermal transport as qualitatively evidenced by micro-Raman characterizations. The significantly enhanced Seebeck coefficients up to 550 μV K⁻¹ and the corresponding power factor of ∼46 μW cm⁻¹ K⁻² revealed comparable to or higher than previously reported values for BST or BST-based nanocomposites, which evidently originated from the presence of multiple BST:DLC hetero-interfaces as clarified in the Pisarenko plot.