Electronic noise of warm electrons in semiconductors from first principles

Abstract

The ab-initio theory of low-field electronic transport properties such as carrier mobility in semiconductors is well-established. However, an equivalent treatment of electronic fluctuations about a non-equilibrium steady state, which are readily probed experimentally, remains less explored.Here, we report a first-principles theory of electronic noise for warm electrons in semiconductors. In contrast with typical numerical methods used for electronic noise, no adjustable parameters are required in the present formalism, with the electronic band structure and scattering rates calculated from first-principles. We demonstrate the utility of our approach by applying it to GaAs and show that spectral features in AC transport properties and noise originate from the disparate time scales of momentum and energy relaxation, despite the dominance of optical phonon scattering.Our formalism enables a parameter-free approach to probe the microscopic transport processes that give rise to electronic noise in semiconductors.

Quasiballistic electron transport in cryogenic SiGe HBTs studied using an exact, semi-analytic solution to the Boltzmann equation

“…Ref. [50], the only effect of a field term is to modify M and thus change the value of c 1 , and our conclusions are robust to such changes. Second, modern devices may have base doping levels exceeding 10 19 cm −3 [25,27,51] to minimize base resistance and prevent carrier freeze-out.…”

High-field transport and hot electron noise in GaAs from first principles: role of two-phonon scattering

“…As in Ref. [92], the drift term (second term in the left hand side of Eq. 1) is implemented using the finitedifference scheme of Refs.…”

“…The non-linear character of the collision integral makes the numerical solution of the BTE challenging at high electric fields. In our previous framework for warm electrons [92], the collision integral took the typical form in the literature in which the weights are linearized about a deviational occupation ∆f k as defined by f k = f 0 k +∆f k , where f 0 k is the equilibrium Fermi-Dirac distribution. The weights associated with this linearization are:…”

“…With the collision integral modified for high electric fields, the remainder of the steady-state calculation follows the same framework as given in Ref. [92]. In particular, the drift velocity is obtained using Eq.…”

“…20 of Ref. [92]. In this work, we restrict E ≤ 5 kV cm −1 , where E is the magnitude of the electric field, due to the increasing computational cost of incorporating states at higher energies that become occupied as the electric field increases (see Sec.…”