Non-Linear electron mobility in n-doped III-Nitrides

Abstract

A theoretical study of the mobility of n-doped III-Nitrides in wurtzite phase is reported. We have determined the nonequilibrium thermodynamic state of the bulk n-InN, n-GaN, and n-AlN systems -driven far away from equilibrium by a strong electric field -in the steady state, which follows after a very fast transient. For this we solve the set of coupled nonlinear integro-differential equations of evolution of the nonequilibrium thermodynamic variables, for the three materials, to obtain their steady state values. The dependence of the mobility (which depends on the nonequilibrium thermodynamic state of the sample) on the electric field strength and the concentration (of electrons and impurities) is derived, which decreases with the increase of the electric field strength and the concentration of carriers, evidencing the influence of the nonlinear transport involved.Keywords: III-Nitrides; Mobility; Nonlinear transportThe so-called nitride materials, like GaN, InN, and AlN, are presently the object of intense research as a result of the large interest associated with application for blue/UV light emitting diodes and diode lasers [1][2][3][4]. We contribute here a theoretical study consisting in an analysis of the electron mobility in n-doped samples of III-Nitrides -which are large direct-gap strong-polar semiconductors -at moderate to high electric fields. Basically we study transport phenomena which develop in the nonequilibrium thermodynamic state of the resulting "hot plasma" consisting of mobile electrons moving in, and interacting with, the lattice and with impurities, and warmed up by the presence of the electric field.We study transport phenomena which develop in n-doped samples of GaN, InN, and AlN, that is the change in the average energy of electrons and phonons, and the electronic current that ensues as a result of the presence of the electric field. This kind of studies are in general pursued with the help of Monte Carlo-like simulations; instead, we here resort to a powerful, concise, and soundly based kinetic theory for far-from equilibrium systems [5]. It is the one based on a nonequilibrium statistical ensemble formalism [6][7][8], the so-called NESEF for short, which provides an elegant, practical, and physically clear picture for describing irreversible processes, as for example in far-away-from-equilibrium semiconductors which is the case considered here. Moreover, we use the effective-mass approximation and therefore parabolic bands; this implies that in explicit applications it needs to be taken into account that there exists an upper limiting value for the electric field strength, corresponding to values below which intervalley scattering can be neglected. In this work we consider the contributions to the mobility arising out of the different channels of electron scattering, namely, the polar-optic, deformation, and piezoelectric interactions with the phonons, and the interaction with impurities. For numerical calculations we used the same characteristic parameters indicated in Ref. [9].Pro...

Anodic stripping voltammetry of silver(I) using unmodified GaN film and nanostructure electrodes

“…We choose GaN because of its excellent physical and chemical properties. It possesses unique electrical properties, low toxicity and excellent chemical stability [13,14]. In particular, wurtzite gallium nitride (GaN), with its remarkable wide direct band gap energy, extremely chemical stability in harsh environment, superior optical property and convenient controlling over its carrier concentration and conductivity type, has been recognized as an attractive candidate for light-emitting diode (LED) [15][16][17], optoelectronic devices [18], DNA biosensor [19], anion and pH selective potentiometric sensor [20,21], monitoring pH in aqueous solution and certain gases at relatively high temperatures.…”

Nonlinear charge transport in highly polar semiconductors: GaN, AlN, InN and GaAs

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Ultrafast dynamics of carriers and phonons of photoinjected double-plasma in aluminium nitride

“…The NE-SOM is a powerful formalism that seems to offer an elegant and concise way for an analytical treatment in the theory of irreversible processes, adequate to deal with a large class of experimental situations, and physically clear picture of irreversible processes. The NESOM is also practical and efficient in the study of the optical and carrier dynamics in semiconductors [36][37][38][39][40][41][42]. More specifically, a Non-Equilibrium Quantum Kinetic Theory [43] derived from NESOM was used in this paper.…”