oedes 0.0.18

organic electronic device simulator

This is work in progress. See doc/ for documentation, and examples/ for examples of use.

Installation

pip install oedes

It is recommended to run test suite after installing

python -c "import oedes; oedes.test()"

Example simulation

This builds and solves a model of abrupt PN junction:

import oedes
from oedes import models

# Define doping profile
def doping_profile(mesh, ctx, eq):
    Nd = ctx.param(eq, 'Nd')
    Na = ctx.param(eq,'Na')
    return oedes.ad.where(mesh.x<mesh.length*0.5,Nd,-Na)

# Define device model
poisson = models.PoissonEquation()
temperature = models.ConstTemperature()
electron = models.BandTransport(poisson=poisson, name='electron', z=-1, thermal=temperature)
hole = models.BandTransport(poisson=poisson, name='hole', z=1, thermal=temperature)
doping = models.FixedCharge(poisson, density=doping_profile)
semiconductor = models.Electroneutrality([electron, hole, doping],name='semiconductor')
recombination = models.DirectRecombination(semiconductor)
anode = models.OhmicContact(poisson, semiconductor, 'electrode0')
cathode = models.OhmicContact(poisson, semiconductor, 'electrode1')
equations=[ poisson, temperature, electron, hole,
            doping, semiconductor, anode, cathode,
            recombination ]

# Define device parameters
params={
    'T':300,
    'epsilon_r':12,
    'Na':1e24,
    'Nd':1e24,
    'hole.mu':1,
    'electron.mu':1,
    'hole.energy':-1.1,
    'electron.energy':0,
    'electrode0.voltage':0,
    'electrode1.voltage':0,
    'hole.N0':1e27,
    'electron.N0':1e27,
    'beta':1e-9
}

# Discretize and solve discrete model
mesh = oedes.fvm.mesh1d(100e-9)
model = oedes.fvm.discretize(equations, mesh)
c=oedes.context(model)
c.solve(params)

# Plot bands and quasi Fermi potentials
import matplotlib.pylab as plt
p=c.mpl(plt.gcf(), plt.gca())
p.plot(['electron.Eband'],label='$E_c$')
p.plot(['hole.Eband'],label='$E_v$')
p.plot(['electron.Ef'],linestyle='--',label='$E_{Fn}$')
p.plot(['hole.Ef'],linestyle='-.',label='$E_{Fp}$')
p.apply_settings({'xunit':'n','xlabel':'nm'})
p.ax.legend(loc=0,frameon=False)
plt.show()