Laser Shock Dislocation Proliferation Drives Enhanced Thermoelectric Performance in Ag₂Se

Dense dislocations effectively reduce the thermal conductivity, thereby enhancing the zT of thermoelectric materials. However, the general down-top strategy involves doping screened elements and synthetic processing, thereby reducing its universality. In this paper, laser shock dislocation proliferation (LSDP) is utilized to construct ∼10¹³/cm² dislocations into Ag₂Se material, which is 2-3 orders higher than spark plasma sintering (SPS) samples. Theoretical analysis demonstrates that the peak pressure exceeds 4.5 GPa, while the effective pressure duration reaches 198 ns, with the impact depth exceeding 0.5 mm and the strain rate reaching 1.52 × 10⁷ s^-1. The introduction of dense dislocations via laser shock reduced the total thermal conductivity by 23.2% and the lattice thermal conductivity by 17.1%. Using a double-sided shock strategy achieved a zT of 0.91, a 40% increase over the SPS samples. This work demonstrates the effectiveness of LSDP in constructing dense dislocations in brittle thermoelectric materials.