Yb Doping Regulation for Synergistic Optimization of Electrical, Thermal Transport and Mechanical Properties in In2O3-Based Thermoelectric Materials

To address the long-standing bottleneck of inherent trade-off between thermoelectric performance and mechanical stability in pure In2O3 thermoelectric materials, this study puts forward a novel optimization route by innovatively adopting Yb2O3 as the dopant, pioneering the dual regulation of defect engineering and electronic structure reconstruction to achieve synchronous thermoelectric–mechanical property synergy, which breaks the limitation of traditional single-property doping modification for oxide thermoelectrics. For electrical transport, Yb3+ induces oxygen vacancy donor defects to boost carrier concentration, and targeted orbital hybridization narrows the band gap and elevates density of states near the Fermi level, synergistically lifting conductivity and offsetting the weakened Seebeck coefficient to optimize power factor with he maximum power factor improved from 1.83 μWm−1K−2 to 5.67 μWm−1K−2. For thermal transport, doping-induced lattice distortion and multi-scale defect system build intensive phonon scattering centers, sharply suppressing lattice thermal conductivity and lowering total thermal conductivity. This synergistic optimization pushes the maximum ZT value to 0.358, a remarkable breakthrough for In2O3-based materials. Meanwhile, Yb2O3 doping reinforces Vickers hardness via lattice distortion strengthening and defect bonding enhancement, eliminating the inherent performance trade-off. This work verifies Yb2O3 doping as a highly efficient strategy, offering solid theoretical basis and practical guidance for developing high-performance, high-stability oxide thermoelectric materials for practical applications.