Nonlocal and nonlinear transport in semiconductors: Real-space transfer effects

Abstract

The contributions of nonlocal mechanisms to nonlinear transport in semiconductors, with special emphasis on hot-electron emission at heterojunctions and its variations which are now commonly termed real-space transfer effects, are reviewed. The goal is to equitably account for and bring together the body of literature that has developed, often independently, in the U.S. and the former Soviet Union as well as in Europe and Japan.

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“…As mentioned above, electrons inside SWs have low mobilities due to the strong scattering by impurities, dislocations and optical phonons at high temperatures. The typical values of electron mobilities in SW SW  are the order of few hundreds cm 2 /V•s [19,23]. It allows us to use Ohm's law for the current flowing through SWs.…”

“…The phenomena of RST is referred to as transfer of hot electrons in the direction perpendicular to heterolayers due to the heating effect in the electric fields applied in the direction along heterolayers. There are number of papers published in the past where RST was measured and explained [19][20][21][22].…”

The 2DEG mobility enhancement for low- and high-electric fields in a new type of AlGaAs/InGaAs heterostructures with donor-acceptor doping

“…It has been theoretically predicted that electron and phonon quantization leads to a decrease in the energy relaxation rate of hot electrons and, therefore, allows enhancing ultimate parameters of high-electron mobility transistors (HEMT) [1]. In rather shallow QWs these effects are masked by the real space transfer effect (RST) [2] i.e. the hot electrons escape from a QW into the barriers when the mean electron energy accelerated by a high electric field becomes comparable with the band-gap discontinuity.…”

Three-terminal laser structure for high-speed modulation using dynamic carrier heating

“…When deriving this formula, only the transitions in real space between equivalent valleys are taken into account, 19,21 and scattering by thermalized carriers is considered as the dominant energy relaxation process for hot electrons entering the AR. Then, the mobility and the energy relaxation rate in Eq.…”

“…19 Here, as a first step, it is assumed that the energy distribution of electrons into the InGaAsP launcher is Maxwellian and spatially uniform. Then, ⌫-L nonparabolic conduction band model is used for this layer.…”