Thermoelectric performance enhancement in p -type Si via dilute Ge alloying and B doping

Majority of the modern electronics are made up of Si owing to a confluence of beneficial properties such as Earth-abundance, non-toxicity, light-weightedness, and versatile dopability. Yet, the thermoelectric performance of Si is not widely explored, due to the relatively high thermal conductivity of undoped Si. In this work, we devised a strategy combining light Ge alloying and B doping to simultaneously enhance the electronic properties and drastically reduce the thermal conductivity of Si. The phonon scattering brought about by Ge atoms, and optimal carrier concentration brought about by B dopant optimizes the thermal and electronic properties. Consequently, zT of 0.14 was achieved at 873 K for Si 0.97 Ge 0.01 B 0.02 , corresponding to 230% enhancement compared to pristine Si. The strategy reported in this work can be extended to the design of high thermoelectric performance in other Si-based compounds.