Bi2Te3 Plates with Single Nanopore: The Formation of Surface Defects and Self-Repair Growth
Abstract
Self-assembly has proven to be a powerful method of preparing structurally intricate nanostructures. In this work, we design a nanoscale "Chinese Coin" based on Bi2Te3 nanoplates (NPs) by using a simple and scalable solution process; i.e., a single pore is introduced on a hexagonal/round plate similar to a fender washer. The diameter of the nanopores is well controlled within the range of 5-100 nm and depends strongly on the reaction time and heating temperatures, suggesting a kinetics related mechanism. Moreover, the thermal evolution of stable Bi2Te3 plate-pore structures was systematically explored to elucidate the underlying energetics of the V2-VI3 chalcogenides. We found that the nanopore is initiated near the middle of the plate, followed by the successive removal of Bi2Te3 slices from the high edge-energy pore with increased temperatures (70-150 °C), leading finally to the formation of a stable nanopore. The morphology of the pore as well as the local lattice crystallinity was studied using high-resolution transmission electron microscopy and first-principles calculations. On the basis of these observations, a self-repair mechanism for pores under the stability diameter is proposed from the viewpoint of reaction kinetics.