import numpy as np
import matplotlib.pyplot as plt
from solcore import siUnits, material, si
from solcore.solar_cell import SolarCell
from solcore.structure import Junction, Layer
from solcore.solar_cell_solver import solar_cell_solver, default_options
from solcore.light_source import LightSource
from solcore.state import State
incidence_angle = 45 # should be in degrees
wl = np.linspace(290, 1900, 400) * 1e-9
concX=566 # the light concentration
light_source = LightSource(source_type='standard', version='AM1.5d', x=default_options.wavelength,
output_units='photon_flux_per_m', concentration=concX) # define the input light source as AM1.5G
all_materials = []
Al2O3 = material('Al2O3')
TiO2 = material('TiO2')
AlInP = material("AlInP")
GaInP = material("GaInP")
GaAs = material('GaAs')
Ge = material("Ge")
Al02Ga08As = material('AlGaAs')
Al08Ga02As = material('AlGaAs')
TOP CELL - GaInP
ARC1= Al2O3()
ARC2 = TiO2()
top_window_material = AlInP(Al=0.5)
top_cell_n_material = GaInP(In=0.51,Nd=siUnits(2e18, "cm-3"), hole_diffusion_length=si("300nm"))
top_cell_p_material = GaInP(In=0.51,Na=siUnits(1.5e17, "cm-3"), electron_diffusion_length=si("2um"))
top_cell_TJ_material = Al08Ga02As(Al=0.8)
for mat in [top_cell_n_material, top_cell_p_material]:
mat.band_gap = material('GaInP')(In=0.51).band_gap
mat.eff_mass_hh_z = material('GaInP')(In=0.51).eff_mass_hh_z
mat.eff_mass_electron = material('GaInP')(In=0.51).eff_mass_electron
mat.relative_permittivity = 11.75
all_materials.append(ARC1)
all_materials.append(ARC2)
all_materials.append(top_window_material)
all_materials.append(top_cell_n_material)
all_materials.append(top_cell_p_material)
all_materials.append(top_cell_TJ_material)
MID CELL - InGaAs
mid_window_material = GaInP(In=0.51)
mid_cell_n_material = GaAs(Nd=siUnits(2e18, "cm-3"), hole_diffusion_length=si("300nm"))
mid_cell_p_material = GaAs(Na=siUnits(1.5e17, "cm-3"), electron_diffusion_length=si("3um"))
mid_BSF_material = GaInP(In=0.51)
mid_cell_TJ_material = Al08Ga02As(Al=0.8)
for mat in [mid_cell_n_material, mid_cell_p_material]:
mat.band_gap = material('GaAs')(In=0.01).band_gap
mat.eff_mass_hh_z = material('GaAs')(In=0.01).eff_mass_hh_z
mat.eff_mass_electron = material('GaAs')(In=0.01).eff_mass_electron
mat.relative_permittivity = 13.1
all_materials.append(mid_window_material)
all_materials.append(mid_cell_n_material)
all_materials.append(mid_cell_p_material)
all_materials.append(mid_BSF_material)
all_materials.append(mid_cell_TJ_material)
DBR1 = Al02Ga08As(Al=0.2)
DBR2 = Al08Ga02As(Al=0.8)
all_materials.append(DBR1)
all_materials.append(DBR2)
BOTTOM CELL - Ge
bot_buffer_material = GaAs()
bot_nucleation_material = GaInP(In=0.51)
bot_cell_n_material = Ge(Nd=siUnits(2e18, "cm-3"), hole_diffusion_length=si("800nm"))
bot_cell_p_material = Ge(Na=siUnits(1e17, "cm-3"), electron_diffusion_length=si("50um"))
for mat in [bot_cell_n_material, bot_cell_p_material]:
mat.band_gap = material('Ge')().band_gap
mat.eff_mass_hh_z = material('Ge')().eff_mass_hh_z
mat.eff_mass_electron = material('Ge')().eff_mass_electron
mat.relative_permittivity = 16
all_materials.append(bot_buffer_material)
all_materials.append(bot_nucleation_material)
all_materials.append(bot_cell_n_material)
all_materials.append(bot_cell_p_material)
We add some other properties to the materials, assumed the same in all cases, for simplicity.
If different, we should have added them above in the definition of the materials.
for mat in all_materials:
mat.hole_mobility = 3.4e-3
mat.electron_mobility = 5e-2
ARC = [Layer(si('80nm'), material = ARC1), Layer(si('33nm'), material = ARC2)]
top_junction = [Junction([Layer(si("18nm"), material=top_window_material, role='window'),
Layer(si("100nm"), material=top_cell_n_material, role='emitter'),
Layer(si("891.248nm"), material=top_cell_p_material, role='base'),
Layer(si("111.445nm"), material = top_cell_TJ_material, role = 'TJ')
], sn=1, sp=1, kind='DA')]
middle_junction = [Junction([Layer(si("18nm"), material=mid_window_material, role='window'),
Layer(si("100nm"), material=mid_cell_n_material, role='emitter'),
Layer(si("1632.091nm"), material=mid_cell_p_material, role='base'),
Layer(si("10nm"), material = mid_BSF_material, role = 'BSF'),
Layer(si("91.084nm"), material=mid_cell_TJ_material, role='TJ')
], sn=1, sp=1, kind='DA')]
DBRa = 16 * [Layer(width=si("62.638nm"), material=DBR1), Layer(width=si("71.980nm"), material=DBR2)]
DBRb = 16 * [Layer(width=si("68.919nm"), material=DBR1), Layer(width=si("78.725nm"), material=DBR2)]
DBRc = 16 * [Layer(width=si("75.838nm"), material=DBR1), Layer(width=si("86.805nm"), material=DBR2)]
# the 4* here makes the two layers given repeat 4 times (so 8 layers total)
bottom_junction = [Junction([Layer(si("405.048nm"), material=bot_buffer_material, role='window'),
Layer(si("14.369nm"), material=bot_nucleation_material, role='window'),
Layer(si("200nm"), material=bot_cell_n_material, role='emitter'),
Layer(si("29800nm"), material = bot_cell_p_material, role = 'base')
], sn=1, sp=1, kind='DA')]
# And, finally, we put everything together, adding also the surface recombination velocities sn and sp.
# setting kind = 'DA' in the Junction definition tells the electrical solver later to use the depletion approximation
optical_struct = SolarCell(ARC + top_junction + middle_junction + DBRa + DBRb + DBRc + bottom_junction,
shading = 0.05)
wl = np.linspace(250, 1700, 400)*1e-9
options = State()
options.wavelength = wl
options.optics_method = 'TMM'
options.no_back_reflection = False
options.pol = 'p'
options.BL_correction = True
options.coherency_list = 111*['c']
options.theta = 30
solar_cell_solver(optical_struct, 'qe', options)
plt.figure()
plt.plot(wl*1e9, optical_struct[0].layer_absorption+optical_struct[1].layer_absorption)
plt.plot(wl*1e9, optical_struct[2].layer_absorption)
plt.plot(wl*1e9, optical_struct[3].layer_absorption)
plt.plot(wl*1e9, optical_struct[100].layer_absorption)
plt.plot(wl*1e9, optical_struct.absorbed, '--')
plt.plot(wl*1e9, optical_struct.transmitted, '--')
plt.plot(wl*1e9, optical_struct.reflected, '--')
plt.legend(['ARC', 'top', 'middle', 'bottom', 'A', 'T', 'R'])
plt.ylim(0,1)
plt.ylabel('Absorption/Transmission/Reflection')
plt.xlabel('Wavelength (nm)')
plt.show()
plt.figure()
plt.plot(wl*1e9, 100*optical_struct[2].eqe(wl))
plt.plot(wl*1e9, 100*optical_struct[3].eqe(wl))
plt.plot(wl*1e9, 100*optical_struct[100].eqe(wl))
plt.plot(wl*1e9, 100*optical_struct.absorbed, '--')
plt.legend(['top', 'middle', 'bottom', 'A'])
plt.ylim(0,100)
plt.ylabel('EQE (%)')
plt.xlabel('Wavelength (nm)')
plt.show()