▎ 摘　　要

Amplification of acoustic in-plane phonons due to an external temperature gradient (del T) in single-layer graphene (SLG) was studied theoretically. The threshold temperature gradient (del T)(0)(g) and the threshold voltage (V-T)(0)(g) in SLG were evaluated. For T = 77 K, the calculated value for (del T)(0)(g) = 746: 8 K/cm and (V-T)(0)(g) = 6.6mV. The calculation was done in the hypersound regime. Further, the dependence of the normalized amplification (Gamma/Gamma(0)) on the frequency omega(q) and del T/T were evaluated numerically and presented graphically. The calculated threshold temperature gradient (V-T)(0)(g) for SLG was higher than that obtained for homogeneous semiconductors (n-InSb) (del T)(0)(hom) approximate to 10(3) K/cm, superlattices (del T)(0)(SL) approximate to 384 K/m, and cylindrical quantum wire (del T)(0)(cqw) approximate to 10(2) K/cm. This makes SLG a much better material for thermoelectric phonon amplification. Published by AIP Publishing.