1. Nonequilibrium Green’s Function with Electron-Phonon Interactions
Objective:
Modeling of electron-phonon interactions for NEGF simulations within the effective-mass and Hartree approximations
Approach:
Employ the self-consistent Born approximation for phonon self-energy functions
Select some peak values of phonon dispersion such as
Elastic intra-valley process
Inelastic inter-valley processes
Impact:
Introducing phase-breaking and energy-relaxation processes into NEGF simulations
More efficient calculations than tight-binding NEGF ρ
(g/cm3) ul
(cm/s) MA
(eV)
2.33
9.05*105
8.90
Mode
(type) MO
(108eV/cm) ħω
(meV)
TA (g)
0.470
12.1
LA (g)
0.740
18.5
LO (g)
10.23
62.0
TA (f)
0.280
19.0
LA (f)
1.860
47.4
TO (f)
58.6
1 intra-valley and
6 inter-valley scattering modes
Electron density (left) and current density (right) spectrums of silicon nanowire transistors with electron phonon-interactions
Result:
We can predict the effect of electron-phonon scattering on silicon nanowire transistors. Ballistic assumption overestimates currents.