High-Entropy Trace Intercalation in Layered Semiconductors: Synergistically Optimized Thermoelectric Performance via Entropy-Driven Transport Decoupling

Intercalation effectively enhances the thermoelectric performance of layered semiconductors. However, conventional strategies employing a single metal element at low concentrations yield limited improvements, typically failing to achieve a zT value greater than 0.5 in intrinsic transition metal dichalcogenides (TMDCs). Here, we propose a ​high-entropy trace intercalation​ strategy by incorporating multi-component metal atoms into TiS 2 . Remarkably, a high thermoelectric figure of merit ( zT ≈ 0.7 at 723 K) is realized, attributed to the simultaneous optimization of thermal and electronic properties: reduced total thermal conductivity κ and high power factor ( PF ) with enhanced weighted mobility. Key characteristics at the optimized intercalation content ( x  = 0.02) include minimized lattice thermal conductivity ( κ L ), sound velocity, and elastic moduli. The outstanding performance stems from ​entropy-engineering, where optimized intercalation (∼2%) induces a substantial entropy enhancement by 33%, generating pronounced lattice disorder and anharmonicity. Critically, this strategy avoids the increase in κ L typically associated with higher intercalant concentrations while maintaining low effective charge doping, thereby minimizing κ . Meanwhile, favorable charge transfer from the intercalation layer to the conduction layers, along with entropy-driven band renormalization, enhances the electrical transport properties. This work establishes high-entropy trace intercalation as a universal paradigm for decoupling electronic and thermal transport in layered thermoelectrics.