N. A. Zakhleniuk

Influence of Field Plate on the Transient Operation of the AlGaN/GaN HEMT

In this letter, a link between the AlGaN/GaN high-electron-mobility-transistor (HEMT) field plate (FP) and the rate of reoccupation of surface traps is presented. Surface traps are considered to be among the primary factors behind HEMT performance deterioration at high frequencies. Results from simulations using the commercial software package DESSIS are presented, in which the FP is found to reduce trap reoccupation by limiting the tunneling injection of electrons into surface traps in the gate-drain region and thus considerably improve the transient operation of the device.

MULTISUBBAND HOT-ELECTRON TRANSPORT IN GAN-BASED QUANTUM WELLS

A simple rigorous analytical theory of two-dimensional (2D) nonequilibrium electrons occupying an arbitrary number of subbands in a quantum well is developed. The electric-field dependence of electron mobility and the average kinetic energy for AlN/GaN quantum wells are presented. At temperatures below 200 K the electron mobility is controlled mainly by the acoustic phonon scattering and it is a nonmonotonous function of the electric field, which has a maximum. At room and higher temperatures the interaction with both acoustic and polar optical phonons determine the hot-electron mobility and it depends very weakly on the electric field. Both the mobility and average energy of 2D electrons are smaller than that for three-dimensional (3D) electrons in the bulk semiconductor. Our theory provides a self-consistent transition from the 2D to the 3D regime of electron transport with increasing electric field accompanied by the occupation of an increasingly large number of subbands by the electrons.

Comparative analysis of zinc-blende and wurtzite GaN for full-band polar optical phonon scattering and negative differential conductivity

For high-power electronics applications, GaN is a promising semiconductor. Under high electric fields, electrons can reach very high energies where polar optical phonon (POP) emission is the dominant scattering mechanism. So, we undertake a full-band analysis of POP scattering of conduction-band electrons based on an empirical pseudopotential band structure. To uncover the directional variations, we compute POP emission rates along high-symmetry directions for the zinc-blende (ZB) crystal phase of GaN. We also compare the results with those of the wurtzite phase. In general, the POP scattering rates in the zinc-blende phase are lower than the wurtzite phase. Our analysis also reveals appreciable directional dependence, with the Γ–L direction of ZB GaN being least vulnerable to POP scattering, characterized by a scattering time of 11 fs. For both crystal phases, we consider the negative differential conductivity possibilities driven by the negative effective mass part of the band structure. According to ou...

Carrier-induced refractive index change and optical absorption in wurtzite InN and GaN: Full-band approach

Based on the full band electronic structure calculations, first we consider the effect of n-type doping on the optical absorption and the refractive index in wurtzite InN and GaN. We identify quite different dielectric response in either case; while InN shows a significant shift in the absorption edge due to n-type doping, this is masked for GaN due to efficient cancellation of the Burstein-Moss effect by the band gap renormalization. For high doping levels the intraband absorption becomes significant in InN. Furthermore, we observe that the free-carrier plasma contribution to refractive index change becomes more important than both band filling and the band gap renormalization for electron densities above 10

Hydrodynamic simulation of surface traps in the AlGaN/GaN HEMT

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Effects of a monolayer on the electron-phonon scattering rates in a quantum well: Dielectric continuum versus hybrid model

~cm

Modified Fabry–Perot and Rate Equation Methods for the Nonlinear Dynamics of an Optically Injected Semiconductor Laser

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Dynamics of Optically-Injected Semiconductor Lasers Using the Travelling-Wave Approach

in GaN, and 10

THE BLOCH-GRUNEISEN MOBILITY OF TWO-DIMENSIONAL ELECTRON GAS IN ALGAN/GAN HETEROSTRUCTURES

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Hot electron capture and power loss in 2D GaN

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