Thermoelectric performance in n-type bulk silicon: The influence of dopant concentration and dopant species

Nick S. Bennett

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Silicon (Si) has received recent interest for thermoelectric (TE) applications. For all TE materials, accurately tuning the doping concentration remains the easiest way to maximise the thermoelectric figure-of-merit (ZT). This study investigates the thermoelectric properties at 300 K of n-type Si as a function of both dopant concentration (N ∼1019–1020cm−3) and dopant species (P, As and Sb), including measurements of electrical resistivity, thermal conductivity, Seebeck coefficient and Hall mobility. All properties were found to vary as a function of both doping concentration and species, leading to impacts on the ZT. The electrical resistivity was lowest for P-doped Si and highest in Sb-doped Si. For the Seebeck coefficient, the situation was reversed. The thermal conductivity was lowest for Sb-doping and highest in P-doped Si. In all cases As-doping was the intermediate dopant. An optimum doping concentration was realized at a value of ∼6–7 × 1019cm−3, and is similar for both As- and P-doped Si. For Sb-doping, the optimum value is likely to be similar, but the highest doping in commercially available wafers was ∼4 × 1019cm−3. At 300 K, ZT ∼0.010 is achieved for P-doped bulk Si, however the best overall value was for As-doped Si, at ∼0.013. For Sb doping the best value is ∼0.012, though a higher value is likely to be possible, but only if doping levels approximately double the concentrations available for this current study can be achieved in starting substrates. These results provide a useful insight for researchers who are selecting a starting substrate for top-down nano-structuring approaches to Si thermoelectrics, where a wafer with optimised ZT is required.

Original languageEnglish
Article number1700307
JournalPhysica Status Solidi (A) Applications and Materials Science
Issue number7
Early online date9 Jun 2017
Publication statusPublished - Jul 2017


  • dopant
  • silicon
  • thermoelectric

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Electrical and Electronic Engineering

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