The strong thermoelectric effect in nanocarbon generated by the ballistic phonon drag ofelectrons

Abstract

The thermoelectric power and thermoelectric figure of merit for carbon nanostructure consisting of graphite-like(sp2) anddiamond-like (sp3) regions have been investigated. The probability of electron collisions with quasi-ballistic phonons insp2 regions has been analysed for the first time. We have shown that the probability isnot small. We have analysed the influence of various factors on the process ofthe electron–ballistic phonon drag (the phonon drag effect). The thermoelectricpower and thermoelectric figure of merit under conditions of ballistic transportwere found to be substantially higher than those in the cases of drag bythermalized phonons and of electron diffusion. The thermoelectric figure of merit(ZT) in the case of a ballistic phonon contribution to the phonon drag of electrons should be 50 timesthat for chaotic phonons and 500 times that in the case of the diffusion process. In that caseZT should bea record (ZT≥2–3).