Negative differential resistance associated with hot phonons
Abstract
We predict the existence of a hot-phonon negative differential resistance (NDR) in GaN. We show that this is a consequence of a wave-vector dependence of lifetime caused by the effect of coupled plasmon-phonons. Anti-screened long-wavelength modes have shorter lifetimes, screened shorter-wavelength modes have longer lifetimes, the boundary between them being determined by the temperature-dependent Landau damping. The higher density of screened modes means that the average lifetime is of order of the lifetime of the bare phonon. Its increase with electron temperature (field) is responsible for the NDR. We also find that the momentum relaxation rate (MRR) associated with the absorption of phonons can be negative in some circumstances, which can be seen to be a consequence of the non-uniform distribution of hot phonons in wave-vector space. We also point out that the ultra-short lifetimes sometimes deduced from experiment should more properly be regarded as electron energy- relaxation times.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 15, 2012
- Source ID
- 10.1063/1.4754012
Entities
People
- A. Dyson
- Brian Kidd Ridley
Organizations
- Office of Naval Research
- University of Essex
- University of Hull