The search for innovative and highly effective thermoelectric (TE) materials that are both abundant and eco-friendly is a widely discussed topic. Achieving high ZT values requires optimizing the power factor (S²σ) and minimizing thermal conductivity (κ). However, the connection between these parameters presents a fundamental challenge to material science for optimizing ZT. Nonetheless, researchers have made considerable progress in significantly reducing thermal conductivity and enhancing the electrical conductivity of silicon-germanium alloys. This study delves into the fabrication and characterization of p-type nanocrystalline silicon-germanium (nc-SiGeH) thin films, deposited by plasma-enhanced chemical vapor deposition (PECVD) at 200 °C. A post-deposition annealing process was conducted at 500 °C to improve the TE properties of the thin films. The κ, measured by the 3-omega method, was observed to be 0.63 W/(m·K) at 300 K, resulting in a notably low thermal conductivity value for SiGe alloy. The room-temperature electrical conductivity (σ_RT) was enhanced by two orders of magnitude, with σ_RT increasing from 4.22E-02 S/cm to 2.06 S/cm. Therefore, the p-type nc-SiGeH material obtained in this research displays promising TE properties, making it an ideal candidate for cost-effective and environment-friendly TE energy harvesting applications operating near 300 K. This breakthrough in TE materials has the potential to revolutionize the way we harness energy and make it more sustainable for future generations.