Effect of band-gap tuning on absorption of phonons and acoustoelectric current in graphene nanoribbon

We report the use of Boltzmann Transport Equation (BTE) in the hypersound regime for investigating the generation of acoustoelectric (AE) current in an armchair graphene nanoribbon (AGNR). The AE current obtained was deduced from the absorption due to the Landau damping of quantized sound waves (LD-QSW) energy. By stimulating the AGNR with a non-quantized electric field, the absorption and the AE current were analysed against the frequency, the wavenumber, the width of the bandgap and the drift velocity. The absorption was observed to switch to amplification as the drift velocity was varied. At high drift velocities, the amplitude of the AE current decreases as the band-gap (that depends on the applied electric field) was increased, suggesting a potential use of AGNR in the design of tunable acoustoelectric current devices.