Unleashing the Impact of Topological Surface States on the Thermoelectric Properties of Granular Sb2Te3 Thin Films Deposited on Flexible Substrates

Between thermoelectric materials, topological insulators (TIs) such as Sb2Te3 can effectively decouple phonon and electronic transport. Recent works mostly focused on TI composites or superlattices, where the contribution of the topological surface states (TSS) to the thermoelectric properties is ov...

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Detalles Bibliográficos
Autores: Locatelli, Lorenzo, Rossi, Pietro, Kumar, Arun, Wiemer, Claudia, Lamperti, Alessio, Mantovan, Roberto, Raciti, Grazia, Xu, Kai, Reparaz, J. Sebastian, Caironi, Mario, Pace, Giuseppina
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/396346
Acceso en línea:http://hdl.handle.net/10261/396346
https://api.elsevier.com/content/abstract/scopus_id/105007928286
Access Level:acceso abierto
Palabra clave:MOCVD
Sb2Te3
Topological insulators
Flexible thermoelectrics
Thin film
Descripción
Sumario:Between thermoelectric materials, topological insulators (TIs) such as Sb2Te3 can effectively decouple phonon and electronic transport. Recent works mostly focused on TI composites or superlattices, where the contribution of the topological surface states (TSS) to the thermoelectric properties is overshadowed by other mechanisms such as energy filtering or electronic band reorganization. Here, we investigate efficient thermoelectric Sb2Te3 polycrystalline thin films deposited on plastic foil. Magneto-transport studies show that the presence of TSS in more granular films is responsible for the 2-orders of magnitude higher electronic conductivity compared to thick films owing to larger crystalline domains (> 100 nm). The prevalence of the bulk states in thick films reduces both their thermal and electronic conductivity; however, they are responsible for an increase in the Seebeck coefficient. Overall, we show that to achieve higher thermoelectric performance of single-component TI films, it is necessary to tune the relative contribution of topological and bulk states. This will potentially allow for the development of cost-effective thermoelectric generators, reducing the complexity of competitive systems based on multicomponent heterostructures.