Publication Date:
2016-07-08
Description:
Amplification of acoustic in-plane phonons due to an external temperature gradient (∇ T ) in single-layer graphene (SLG) was studied theoretically. The threshold temperature gradient ( ∇ T ) 0 g and the threshold voltage ( V T ) 0 g in SLG were evaluated. For T = 77 K , the calculated value for ( ∇ T ) 0 g = 746.8 K / cm and ( V T ) 0 g = 6.6 mV . The calculation was done in the hypersound regime. Further, the dependence of the normalized amplification ( Γ / Γ 0 ) on the frequency ω q and ∇ 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) ( ∇ T ) 0 hom ≈ 10 3 K / cm , superlattices ( ∇ T ) 0 S L ≈ 384 K / cm , and cylindrical quantum wire ( ∇ T ) 0 c q w ≈ 10 2 K / cm . This makes SLG a much better material for thermoelectric phonon amplification.
Print ISSN:
1063-777X
Electronic ISSN:
1090-6517
Topics:
Physics