Generation of acousto-electric direct current in fluorine-doped single-walled carbon nanotubes due to the mixing of waves with commensurate frequencies (phaseless)

We theoretically report on the acousto-electric direct current (ADC) generation in non-degenerate fluorine-doped single-walled carbon nanotubes (FSWCNTs). Our calculation on the carriers in the lowest miniband, where waves with commensurate frequencies (zero phase difference) mix in the hypersound region (qℓ≫1 where q is the acoustic phonon wave number and ℓ is the carrier mean free path). The generated DC exhibits strong nonlinear and non-ohmic behaviour, dependent on the magnitude of the AC fields (E1 and E2), overlapping integral for leaps (Δs and Δz), carrier concentration (n0), Bloch frequency (Ω), acoustic phonon frequency (ωq) and photon frequency (ωi). The non-ohmicity in the observed I–V characteristics likely originates from a combined non-parabolicity of the band relation, Stark effect, charge carrier heating, intraminiband carrier oscillation and parametric resonance. Notably, the generated DC corresponded to even instability regions in the FSWCNTs as promising candidates for ADC generation under bichromatic fields with commensurate frequencies.