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

• Published in: Journal of materials science 2022-11, Vol.57 (43), p.20299-20308
• Main Authors: Solco, Samantha Faye Duran, Tan, Xian Yi, Zhang, Danwei, Cao, Jing, Wang, Xizu, Zhu, Qiang, Wang, Suxi, Chew, Li Tian, Liu, Hongfei, Tan, Chee Kiang Ivan, Wu, Jing, Tan, Dennis Cheng Cheh, Xu, Jianwei, Suwardi, Ady
• Format: Article
• Language: English
• Subjects: Alloying; Boron; Carrier density; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Doping; Efficiency; Electric properties; Electronic Materials; Electronic properties; Engineering; Germanium; Heat conductivity; Heat transfer; Materials Science; Performance enhancement; Plasma sintering; Point defects; Polymer Sciences; Silicon compounds; Solid Mechanics; Specialty metals industry; Thermal conductivity; Thermoelectricity; Toxicity
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-022-07925-y

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.