Fabrication and Characterization of a Hybrid Bi2Se3/Organic Superlattice for Thermoelectric Energy Conversion

Abstract

AbstractHybrid inorganic/organic thermoelectric materials have recently gained increasing research interest, due to their mechanical flexibility and the wide tunability of their components and properties. In this Communication, a new strategy to fabricate an inorganic/organic superlattice of Bi2Se3hexylamm‐onium0.11dimethylsulfoxide0.06 (Bi2Se3HA0.11DMSO0.06) through a series of chemical reaction processes, including lithium intercalation, ionic exchange, and organic exchange, is put forward. It is shown that the organic molecules expand the interlayer space between the Bi2Se3 layers and form a triple‐layer structure, where the hexylammonium ions are ionically bonded to the negatively charged Bi2Se3 layers. The lattice vibration modes of the Bi2Se3 layers in this hybrid superlattice are found to be softened due to weakened interlayer interaction and phonon confinement effect. The hybrid Bi2Se3HA0.11DMSO0.06 shows a power factor of 950 µW m−1 K−2 at room temperature, among the best in n‐type flexible thermoelectric materials. A huge reduction of thermal conductivity is observed, which contributes to the large enhancement of zT value. The current research on Bi2Se3‐based inorganic/organic superlattices can stimulate exploration of novel high‐performance flexible thermoelectric materials by hybridizing inorganic and organic materials at the atomic scale.