Thermoelectric materials hold immense potential for energy recovery and environmental protection, while thermoelectric films can also effectively dissipate heat from chips through thermoelectric cooling. WS₂ films exhibit promising thermoelectric performance in predictions, but the thermoelectric figure of merit (ZT) of synthesized WS₂ films still requires improvement. In this work, we doped copper (Cu) into WS₂ films via magnetron sputtering combined with chemical vapor deposition. Cu doping narrowed the bandgap and increased the hole concentration from 5.6 × 10¹⁹ cm^-3 to 2.2 × 10²¹ cm^-3, significantly improving the electrical performance of WS₂ films. At 300 K, the conductivity and power factor of the Cu-doped film increased by 1086% and 575%, respectively, compared to the WS₂ film. Furthermore, Cu doping reduced grain size and introduced more grain boundaries, lowering the in-plane thermal conductivity to 0.22 W m^-1 K^-1 at 300 K. The synergistic optimization of electrical and thermal properties substantially enhances the ZT value. The ZT value of Cu_5.5-WS₂ films reaches 0.181 at 425 K. This work provides new insights for improving the thermoelectric performance of transition metal dichalcogenide (TMDC) films.

Cu doping;DFT calculations;WS2 thin films;Synergistic regulation;Thermoelectric performance