• • Co-doping enables simultaneous band convergence and dopability preservation, overcoming the limitation of reduced acceptor dopability seen in single mono-telluride alloying, which is critical for maintaining optimal carrier concentrations.
• • The approach introduces lattice dislocations that strongly scatter phonons, substantially reducing lattice thermal conductivity, as evidenced by the extraordinary peak zT values reported.
• • The decoupling of electronic and thermal transport achieved through co-doping results in a peak figure of merit exceeding previously reported values for PbTe-based systems, demonstrating the effectiveness of this strategy.
• • The study provides a pathway to optimize thermoelectric performance by addressing the intrinsic coupling of Seebeck coefficient, electrical conductivity, and thermal conductivity, which is essential for practical applications in waste heat recovery and solid-state cooling.