Advances and challenges of Bi₂Te₃: exploring the intersection of thermoelectricity and topological properties

Bi₂Te₃, a member of quintessential V₂VI₃chalcogenide family, is not only widely utilized as significant thermoelectric (TE) material near room temperature but also an archetypical topological insulator, characterized by topological surface states protected by time-reversal symmetry. Bi₂Te₃based materials have garnered global attention due to its excellent TE proficiency, making it ideal for use in highly efficient TE coolers and compact, flexible TE power generators for various electronic devices. Additionally, fascinating topological phenomena, such as the topological insulating behavior, quantum anomalous Hall effect and topological superconductivity observed in Bi₂Te₃based samples, have significantly influenced the ongoing research in condensed matter physics. Given its multifunctionality, Bi₂Te₃remains a compelling platform for next-generation TEs, dissipationless electronics, spintronics, magneto-electronic sensors, and terahertz optoelectronics. Precise control of synthesis protocols, microstructures, and strategic manipulation of carrier as well as phonon transport are essential for both successful device operation and experimental realization of unique topological phenomena. This review highlights recent advancements in inherent defect engineering, carrier concentration tuning and band engineering at both bulk and nanoscale level, focusing on their role in phonon transport (thermal conductivity, anharmonicity, and specific heat) and electronic transport of Bi₂Te₃based samples. Furthermore, Bi₂Te₃based materials are likely to remain a pivotal platform for the exploration and realization of novel topological properties. This motivates us to include a brief overview of physical insights into magneto-transport and quantum transport properties of Bi₂Te₃in the review.