A New Strategy for Realizing the Conversion of “Homo–Hetero–Homo” Heteroepitaxial Growth in Bi2Te3 and the Thermoelectric Performance

Abstract

Uncovering the reason for structure-dependent thermoelectric performance still remains a big challenge. A low-temperature and easily scalable strategy for synthesizing Bi2 Te3 nanostring hierarchical structures through solution-phase reactions, during which there is the conversion of "homo-hetero-homo" in Bi2 Te3 heteroepitaxial growth, is reported. Bi2 Te3 nanostrings are obtained through the transformation from pure Bi2 Te3 hexagonal nanosheets followed by TeBi2 Te3 "nanotop" heterostructures to Bi2 Te3 nanostrings. The growth of Bi2 Te3 nanostrings appears to be a self-assembly process through a wavy competition process generated from Te and Bi(3+) . The conversion of homo-hetero-homo opens up new platforms to investigate the wet chemistry of Bi2 Te3 nanomaterials. Furthermore, to study the effect of morphologies and hetero/homo structures, especially with the same origin and uniform conditions on their thermoelectric properties, the thermoelectric properties of Bi2 Te3 nanostrings and TeBi2 Te3 heterostructured pellets fabricated by spark plasma sintering have been investigated separately.