Resonant tunneling diodes

The RTD from its simplest model to the one that matches experiment: a linear potential drop, realistic doping, relaxation in the reservoirs, Hartree self-consistency, asymmetry and charge accumulation, the recursive Green function that makes it affordable, and the incoherent scattering that fills the valley.

Lecture 11.1

Introduction to resonant tunneling diodes — RTDs with linear potential drops

builds the lecture's RTD (7 nm GaAs well, 5 nm Al${0.3}$Ga${0.7}$As barriers) with a linear potential drop, computes its transmission $T(E)$, the current density spectrum $J(E)$ and its running integral

Lecture 11.2

RTDs with realistic doping profiles

builds an RTD with $10^{18}$ cm$^{-3}$ contacts and 50 nm undoped spacers, solves the Thomas–Fermi/Poisson problem with nemo.thomas_fermi_iv (ballistic current, Fermi level dropping linearly across the device)

Lecture 11.3

Resonant tunneling diodes with relaxation in the reservoirs

uses the realistic-doping RTD of lecture 11.2 and computes the Thomas–Fermi I–V with and without reservoir relaxation (nemo.thomas_fermi_iv(relaxation=...))

Lecture 11.4

RTDs with quantum charge self-consistency (Hartree model)

takes the realistic-doping RTD of lectures 11.2–11.3 and compares the band profiles and I–V curves of a linear drop, the Thomas–Fermi model (nemo.thomas_fermi_iv) and the Hartree model (nemo.hartree_iv)

Lecture 11.5

Asymmetric RTDs with charge accumulation and depletion

builds an RTD with a 5 nm emitter barrier and a 7 nm collector barrier, and its mirror image for reverse bias; it compares the Thomas–Fermi (nemo.thomas_fermi_iv) and Hartree (nemo.hartree_iv) I–V curves

Lecture 12

The recursive Green function algorithm (RGF)

implements the recursive Green function algorithm in NumPy for the single-band RTD of lecture 11.1, checks the diagonal and corner elements of $G^R$ against a dense inverse and the transmission against nemo.Transport

Lecture 13

Incoherent scattering concepts and impact in RTDs

builds a GaAs/Al${0.3}$Ga${0.7}$As RTD on a monolayer grid, computes its Thomas–Fermi potential and then the current with NEMO's k-resolved scattering solver RoughnessTransport (Lake et al. 1997): coherent