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

Abstract Hybrid 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 Bi 2 Se 3 hexylamm‐onium 0.11 dimethylsulfoxide 0.06 (Bi 2 Se 3 HA 0.11 DMSO 0.06 ) 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 Bi 2 Se 3 layers and form a triple‐layer structure, where the hexylammonium ions are ionically bonded to the negatively charged Bi 2 Se 3 layers. The lattice vibration modes of the Bi 2 Se 3 layers in this hybrid superlattice are found to be softened due to weakened interlayer interaction and phonon confinement effect. The hybrid Bi 2 Se 3 HA 0.11 DMSO 0.06 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 Bi 2 Se 3 ‐based inorganic/organic superlattices can stimulate exploration of novel high‐performance flexible thermoelectric materials by hybridizing inorganic and organic materials at the atomic scale.