▎ 摘　　要

We calculate the hot electron energy relaxation P due to acoustic-phonon scattering via deformation potential coupling in an armchair graphene nanoribbon (AGNR). Its dependence on electron temperature T-e, Fermi energy E-f (linear electron concentration n(t)) and width W of AGNR is investigated. At low P is found to be exponentially suppressed contrary to the power laws in graphene and conventional semiconductor nanostructures. This gradually changes to sublinear behavior for an about T-e > 100 K contrary to conventional P similar to T-e. P shows strong dependence on E-f and n(t) and it decreases with the increasing E-f and n(t), at low T-e. At a constant n(t), P varies approximately as W-s with s similar to 2-3. A weak dependence of s on T-e and n(t) is observed. We point out that the low T-e study of P, as it is independent of all non-acoustic phonon scattering mechanisms, could be used to determine the accurate value of acoustic-phonon deformation potential coupling constant in graphene about which there is still uncertainty. (C) 2011 Elsevier B.V. All rights reserved.