Dimensional Crossover Engineering in MoS₂/Organic Superlattices Breaks the zT Barrier for 2D Thermoelectrics.

Abstract

The rapid development of self-powered microelectronics demands thermoelectric devices (TEDs) that can simultaneously achieve high energy conversion efficiency and silicon micro-fabrication compatibility. While for conventional bulk TEs, their incompatibility with silicon micro-manufacturing restricts microelectronic integration. 2D materials, though CMOS-fabrication-friendly and widely explored for microelectronic devices, face critical limitations in thermoelectric energy conversion efficiency due to their low zT values (<0.2) stemming from unfavorable thermal conductivity-power factor tradeoffs. These challenges are overcome through orbital-property-driven dimensional engineering of hybrid MoS₂/organic superlattices, which synergistically enhances electrical transport while suppressing thermal conductivity. Strain-adaptive intercalation of tert-butylamine (TBA) molecules creates MoS₂ bilayer superlattices exhibiting an electronic structure crossover between monolayer-like and bulk-like characteristics, thereby maximizing the density of states near the Fermi level. The optimized MoS₂ bilayer/TBA hybrid superlattice achieves a breakthrough zT of 0.6 at 373 K - 12-fold higher than monolayer counterparts and 100× surpassing bulk crystals. This represents the highest experimentally reported zT for 2D material-based TEDs, approaching performance benchmarks of commercial bulk TEs. The work establishes a paradigm of dimensional engineering in hybrid superlattices, thus enabling integration of high-efficiency 2D materials-based TEDs into silicon microelectronics-a critical step toward self-powered IoT systems and wearable technologies.