Enhancement in Thermoelectrical Power Factor of N-Type Si 80 Ge 20 Alloys

Influences of the carrier concentration and mobility of heavily doped n-type Si 80 Ge 20 alloys on the thermoelectrical power factor are investigated. The experimental results indicate that thermoelectrical power factors of 32–36μW cm −1 K −2 could be consistently achieved with carrier concentrations of 2.1–2.9 × 10 20 cm −3 and carrier mobilities of 36–40 cm 2 V −1 s −1 . However, many samples with suitable carrier concentrations do not always have high mobilities and high power factors. Some possible explanations for this behaviour are discussed.