Combined First-Principles Calculation and Experimental Investigation: Synergistic Modulation of Electronic and Phonon Transport to Enhance Thermoelectric Performance of Ni-Doped ZnO for Intelligent Fabric Defect Detection

Benefiting from outstanding thermal durability at elevated temperatures and eco-friendly characteristics, oxide-based thermoelectric substances exhibit great application potential in residual heat recycling and intelligent textile defect inspection. Zinc oxide (ZnO) exhibits excellent thermal stability but suffers from high lattice thermal conductivity and low carrier concentration. Herein, we systematically investigate Ni-doped ZnO ceramics. XRD(X-ray diffraction) confirms homogeneous wurtzite solid solutions with lattice contraction following Vegard’s law. Ni doping enhances electrical conductivity from 45.45 to 145.80 S·cm−1 by promoting oxygen vacancy formation, while first-principles calculations reveal a narrowed bandgap. For specimens with x ranging from 0.0040 to 0.0044, the power factor attains approximately 8.0 μW·cm−1·K−2 at 873 K, representing a 41% enhancement. Meanwhile, intensified phonon scattering leads to an evident suppression of lattice thermal conductivity, which lowers the overall thermal conductivity down to 2.38 W·m−1·K−1 under 873 K. Benefiting from the above optimizations, the sample delivers a peak thermoelectric figure of merit (ZT) value of 0.27 at this temperature, which is 170% greater than that of undoped ZnO. In addition, the Vickers hardness rises from 242.70 HV to 281.45 HV. Such observations verify that nickel doping can successfully decouple charge and heat transport behaviors. This approach provides a feasible route toward developing oxide thermoelectric systems with upgraded thermoelectric performance.