Monte Carlo simulation of the generation of terahertz radiation in GaN

Abstract

Terahertz generation in submicron GaN diodes within the limited space-charge accumulation regime J. Appl. Phys. 98, 064507 (2005); 10.1063/1.2060956 Monte Carlo study of hot-carrier transport in bulk wurtzite GaN and modeling of a near-terahertz impact avalanche transit time diode J. Appl. Phys. 95, 7925 (2004); 10.1063/1.1702144 Monte Carlo analysis of GaN-based Gunn oscillators for microwave power generation J. Appl. Phys. 93, 4836 (2003); 10.1063/1.1562734 Monte Carlo calculation of electron initiated impact ionization in bulk zinc-blende and wurtzite GaNThe conditions for microwave power generation at low temperatures under optical phonon emission are analyzed by Monte Carlo simulations of both small-and large-signal responses in bulk zinc blende and wurtzite GaN. As a result of the high optical phonon energy and the strong interaction of electrons with optical phonons in GaN a general improvement on the transit-time resonance and a considerable increase in the maximum generation frequency and power can be achieved in comparison to the widely studied III-V materials such as GaAs and InP. A dynamic negative differential mobility caused by transit-time resonance occurs in a wide frequency range of about 0.05-3 THz and persists in the THz frequency range up to the liquid nitrogen temperature with doping levels up to about 5ϫ10 16 cm Ϫ3 . The efficiency of the amplification and generation is found to depend nonmonotonously on static and microwave electric field amplitudes, generation frequency, and doping level so that for each generation frequency there exists an optimal range of parameter values. Under optimal conditions a generation efficiency of about 1% to 2% can be achieved in the 0.5-1.5 THz frequency range.

Generation of TeraHertz radiation assisted by optical phonons in nitride‐based quantum wells and heterolayers

“…(4)] is stronger than in standard III-V materials. This is confirmed by MC simulations of bulk nitrides from which the maximum generation frequency is shown to lie between 1 and 4 THz (going from InN to GaN and to AlN) [2].…”

“…For this sake, the characteristic scattering times, τ − and τ + inside and outside of the optical-phonon sphere in momentum space, respectively (the so called passive and active regions), must satisfy the inequality [1][2][3]:…”

Voltage Controlled Terahertz Transmission Enhancement through GaN Quantum Wells

“…Even if these experimental results have to be improved, specially regarding the frequency band studied in this letter, this dependence could be related to the optical phonon transit time resonance (OPTTR) phenomenon described in Ref. [15].…”

Monte Carlo Calculation of High Frequency Mobility and Diffusion Noise in Nitride-Based Semiconductors

“…For this sake, linear response functions of the longitudinal velocity and differential mobility spectra µ(ω) are calculated by using the technique based on the velocity average over before-and after-scattering ensembles [4] when a constant electric field E is applied to the bulk material. For the noise analysis, the correlation function of longitudinal velocity fluctuations, C vv (s), is calculated and the spectral density of velocity fluctuations, S vv (ω) is then obtained by Fourier transform of C vv (s).…”