Nonlocal Hot-Electron Transport and Capture Model for Multiple Quantum Well Structures Excited by Infrared Radiation

Abstract

In this paper, a model for hot-electron transport and capture phenomena in semiconductor heterostructures with multiple uncoupled quantum wells (QW) excited by infrared radiation is presented. The model takes into account the nonlocal character of the electron transport and capture of mobile electrons propagating over the barriers. It includes the Poisson equation and balance equations for electrons and their energy. The model is used for the calculation of steady-state spatial distributions of the electric-field and the average electron energy in multiple QW structures. The conditions of the formation of periodic electricfield domains revealed recently in ensemble Monte Carlo particle simulations are found. The obtained results are compared with the previous analytical calculations based on a simplified model. The relationships between phenomenological parameters of the latter and QW structure parameters are obtained. The developed analytical model highlights the origin of periodic electric-field domains in multiple QW structures and explains some features of such domain behavior.

Self-organization in multiple quantum well infrared photodetectors

“…In the situation under consideration (in which the electron capture is accompanied by optical phonon emission), a decreasing dependence of the capture rate on the electric field is due to a decrease in the fraction of electrons with energies less than the optical phonon energy when the gas of mobile electrons becomes hotter. As shown theoretically using both a phenomenological model of the capture processes [15] and a model invoking the energy transport equation [23], the recharging instability and the self-organization in question can take place for any capture mechanism whose rate drops with heating.…”

Effect of doping on the characteristics of infrared photodetectors based on van der Waals heterostructures with multiple graphene layers

“…Since the photoexcited and injected electrons acquire kinetic energy propagating across the device under the electric field, they can be hot. If the electron energy relaxation length L ε = v d τ ε , where v d and τ ε are the electron drift velocity and the energy relaxation time, respectively, exceeds the heterostructure period d, the electron effective temperature T ef f is mainly determined by the applied bias voltage V [38]. An increase in V leads to a rise of T ef f and to a drop of the capture efficiency p [26] (see also references therein).…”

Infrared photodetectors based on graphene van der Waals heterostructures

“…It is worth mention that if the capture efficiency p n is a sufficiently strong function of E n−1 , the monotonic electric-field spatial distributions can become unstable against the perturbation with the length 2d [36][37][38]. Such an instability can lead to quasi-chaotic spatio-temporal electric field variations, which eventually result in the formation of stable quasi-periodic electric-field distributions [48].…”

“…In the framework of this concept, the electric-field distributions are assumed to be uniform. A more accurate consideration of the transport phenomena in such structures (including GLIPs) in the dark conditions and under irradiation accounts for the self-consistent electric field distributions and the nonideality of the emitter [32][33][34][35][36][37][38]. This paper uses this more accurate approach.…”