Hot-electron dynamics and terahertz generation in GaN quantum wells in the streaming transport regime

Abstract

We study hot-electron transport and the dynamic negative differential conductivity in a GaN / AlGaN quantum well by using the Monte Carlo method. We find that the electron-electron interaction, the nonequilibrium polar optical phonon, and the electron gas degeneracy may influence the electron transport property and destroy the spindle-shaped distribution in the streaming transport regime. Our simulation results suggest that the hot phonon effect, and the electron gas degeneracy are more important in the determination of electron steady state velocity-field characteristics, while the electron-electron interaction is dominant in the disturbance of the electron periodic motion. We conclude that terahertz generation using the electron dynamic negative differential conductivity is only possible at relatively low electron density before the electron-electron interaction steps into role.

Terahertz generation in nitrides due to transit-time resonance assisted by optical phonon emission

“…In concluding this subsection let us note that more detailed MC results on the DNDM induced by OPTTR and associated features can be found in [11,12,[33][34][35][36][37][38][39]46] for the 3D case and [33,[40][41][42][43][44][45][46] for the 2D case. 4 but normalized to the characteristic po-scattering field E i po and frequency ν i po defined by equations ( 10) and (11), respectively.…”

“…Both the gain and the generated power should increase with the increase of the carrier concentration controlled by the doping level. However, the increase of the carrier concentration in turn decreases the value of − Re[μ ω ], and hence, of both α ω and P ω , due to ionized impurity [34] and electron-electron [44] scattering. The competition between these two opposing tendencies implies the existence of an optimum range of doping level for each generation frequency where the gain and the generated power are maxima.…”

Investigation of terahertz waves propagating through subwavelength metal–dielectric–metal structure

“…Under the framework of TMM, the electric or magnetic field can be written as the summation of the incident waves and the reflected waves in each layer of planar multilayered structure. For the case of TM modes, the boundary condition at the interface can be written as [21,39]:…”

Effects of design parameters on the performance of terahertz quantum-cascade lasers

“…The final states of these two electrons are in a subband f with a wave vector k f and a subband n with a wave vector k 0 , respectively. The scattering rate of the principal electron can be written as [20] if (k…”

“…In our MC simulation, the Pauli exclusion principle will modify the e-e scattering rates. The inclusion of this effect in a MC simulation has been reported in many papers [20][21][22]. We account for degeneracy by tabulating the electron distribution function within each subband during the simulation using a self-scattering rejection technique to accept or reject scattering events based on the final state occupancy [23].…”