Incorporation of metallic yttrium silicide nanoparticles in p-type SiGe alloys matrix is demonstrated to enhance their thermoelectric performance.In this work,we report a thermoelectric figure-of-merit (ZT) of ~1.81 (at 1100 K)in p-type SiGe alloys(that is ~34% higher as compared to earlier best reported ZT value)by intentional incorporation of metallic yttrium silicide (YSi₂) nano-inclusions.The YSi₂ nano-inclusions were in-situ formed in p-type SiGe matrix by its reaction with Y₂O₃ nanoparticles (≤6 wt%) during vacuum hot pressing at 1423K under a pressure of 50kg/cm². YSi² nanoinclusions formcoherent interfaces with SiGe matrix and facilitate are ductionin the grain size of SiGe.These factors cause a strong suppression of thermal conductivity (κ_SiGe
~3.86 Wm^-1 K^-1 and κ_{SiGe-YSi2 ~}
2.38Wm^-1 K^-1 at 1100 K) without affecting the power factor, and therefore, results in a dramatic enhancement of ZT. In addition, SiGe-YSi₂ nanocomposites exhibit enhancement in mechanical hardness,enhanced average ZT as well as compatibility factor, which are additional useful characteristics for practical applications.