| Abstract Scope |
In the past ten years, Bismuth telluride-based thermoelectric (TE) materials have been proved to be widely used in waste heat recovery and electronic coolers. However, the peak zT of n-type counterparts have lower than p-type counterparts, and the peak zT is obtained at higher temperatures. This performance imbalance severely hinders its TE applications. In this work, the TE performance of n-type Bi2Te3 is improved by doping liquid-like copper chalcogenides Cu2X (X = S, Se, Te). Dilute Cu2X dopants are incorporated into Bi2Te3 crystals, aiming to boost carrier mobility by generating the highly-mobile Cu ions. Meanwhile, the dopants introduce nano-precipitates and multiscale crystal imperfections, leading to the κL for our best-performing sample reaching the amorphous limit of Bi2Te3. Hybrid crystalline materials with liquid-like superionic conductors could serve as a new route for alloy design, which decouples the interconnect transfer characteristics for breakthrough TE performance. |