By adding “weakly-active” SGPT and Cu, differentiated electro-phonon scattering centers are induced to significantly suppress κ_ph with μ less affected, leading to a ZT_ave of 1.32 and a η of 6.8%.

The highly active additive Cu₂SnTe₃ generates multi-scale defects, effectively reducing lattice thermal conductivity. Along with optimized weighted mobility, the higher quality factor yields a competitive ZT value in the (Bi,Sb)₂Te₃-based composite.

By introducing the active telluride Ag ₉ GaTe ₆ in p-type Bi _0.4 Sb _1.6 Te ₃ , lath twin boundaries are induced as differential scattering centers for carriers and phonons, leading to improved ZT values and high thermoelectric conversion efficiencies.