Refined Compensation Doping and Off‐Center Distortions Induced Performance Enhancement in N‐Type Skutterudites Thermoelectrics

Abstract The excellent performance of skutterudites is related to the interrelated filling fraction and doping limitation of the intricate matrix. Especially for the investigation of n‐type electronegatively filling samples, the exceptionally low doping capacity at Sb sites leads to severely compromised thermoelectric performance. Here, a breakthrough is achieved in surpassing conventional doping limits by developing a novel “electrical compensation‐bonding modulation” method, contributing to the reconfiguration of the unique X 4 ring structure (Consists of Sb 4 units) in S 0.2 Se 0.05 Co 4 Sb 12‐x Te x skutterudites. The modulated bond hierarchy and disorder enable a concurrent regulation of phonon and carrier transport, resulting in a significant improvement of the transport properties. Building upon this foundation, a revolutionary off‐center state has been introduced to the matrix via continuous doping of Se at Sb sites, aimed at suppressing the lattice thermal conductivity. Ultimately, a peak zT of 1.8 at 800 K is achieved, with an average zT of 1.1 across the 300–800 K temperature range. This work provides a universal approach to overcome doping limits in Co 4 Sb 12 ‐based thermoelectrics.