profile_pass_matrix.py

import numpy as np

from rayflare.textures import regular_pyramids
from rayflare.structure import Interface, BulkLayer, Structure
from rayflare.matrix_formalism import calculate_RAT, process_structure
from rayflare.options import default_options
from rayflare.angles import make_angle_vector
from rayflare.utilities import make_absorption_function


from solcore import material, si
from solcore.solar_cell import SolarCell, Layer, Junction
from solcore.solar_cell_solver import solar_cell_solver
from solcore.light_source import LightSource
from solcore.constants import q
from solcore.absorption_calculator import search_db

# imports for plotting
import matplotlib.pyplot as plt
import seaborn as sns
from cycler import cycler

import os

# GaAs/GaAs/Si solar cell

# ARC

# Electron barrier (GaInP)
# Absorber (GaAs, p on n)
# Hole barrier (GaInP)
# Tunnel - n-GaAs?
# Hole barrier (InAlP)
# Absorber (GaAs, n on p)
# Electron barrier (GaInP)
# n-GaAs bonding
# n-Si
# p-Si
# rear surface:


wavelengths = np.linspace(250, 1200, 100) * 1e-9

options = default_options()
options.wavelength = wavelengths
options.project_name = "GaAs_GaAs_Si"
options.n_theta_bins = 100
options.nx = 5
options.ny = 5
options.depth_spacing = si("1nm")
options.depth_spacing_bulk = si("100nm")
options.phi_symmetry = np.pi / 2
_, _, angle_vector = make_angle_vector(options["n_theta_bins"], options["phi_symmetry"], options["c_azimuth"])
options.bulk_profile = True
options.n_rays = options.nx**2 * int(len(angle_vector) / 2)

# custom materials are in HIT_emissivity.py

Air = material("Air")()
Al2O3 = material("Al2O3")()
Ag = material("Ag_Jiang")()
aSi_i = material("aSi_i")()
aSi_p = material("aSi_p")()
aSi_n = material("aSi_n")()
ITO_back = material("ITO_back")()
GaAs = material("GaAs")()
InAlP = material("AlInP")(Al=0.5)
GaInP = material("GaInP")(In=0.5)
Si = material("Si")()

# download_db() # only need to run this once to download database from refractiveindex.info
MgF2_pageid = str(search_db(os.path.join("MgF2", "Rodriguez"))[0][0])
Ta2O5_pageid = str(search_db(os.path.join("Ta2O5", "Rodriguez"))[0][0])

MgF2 = material(MgF2_pageid, nk_db=True)()
Ta2O5 = material(Ta2O5_pageid, nk_db=True)()

GaAs_1_th = 120e-9
GaAs_2_th = 1200e-9

front_materials = [
    Layer(50e-9, MgF2),
    Layer(40e-9, Ta2O5),
    Layer(30e-9, GaInP),
    Layer(GaAs_1_th, GaAs),
    Layer(30e-9, InAlP),
    Layer(20e-9, GaAs),
    Layer(30e-9, GaInP),
    Layer(GaAs_2_th, GaAs),
    Layer(30e-9, InAlP),
    Layer(100e-9, GaAs),
    Layer(6.5e-9, aSi_p),
    Layer(6.5e-9, aSi_i),
]
back_materials = [Layer(6.5e-9, aSi_i), Layer(6.5e-9, aSi_n), Layer(240e-9, ITO_back)]


surf_back = regular_pyramids(elevation_angle=55, upright=False)

front_surf = Interface("TMM", layers=front_materials, name="GaAs_GaAs", coherent=True, prof_layers=[4, 8])
back_surf = Interface(
    "RT_TMM", texture=surf_back, layers=back_materials, name="Si_HIT_rear", prof_layers=[1, 3], coherent=True
)

bulk_Si = BulkLayer(250e-6, Si, name="Si_bulk")  # bulk thickness in m

SC = Structure([front_surf, bulk_Si, back_surf], incidence=Air, transmission=Ag)

process_structure(SC, options)

results = calculate_RAT(SC, options)


RAT = results[0]
results_per_pass = results[1]

# only select absorbing layers, sum over passes
results_per_layer_front = np.sum(results_per_pass["a"][0], 0)

results_per_layer_back = np.sum(results_per_pass["a"][1], 0)

allres = np.flip(
    np.vstack((RAT["R"], results_per_layer_front[:, 3].T, results_per_layer_front[:, 7].T, RAT["A_bulk"], RAT["T"])), 0
)


spectr_flux = LightSource(
    source_type="standard", version="AM1.5g", x=wavelengths, output_units="photon_flux_per_m", concentration=1
).spectrum(wavelengths)[1]

Jph_GaAs_1 = q * np.trapz(results_per_layer_front[:, 3] * spectr_flux, wavelengths) / 10  # mA/cm2
Jph_GaAs_2 = q * np.trapz(results_per_layer_front[:, 7] * spectr_flux, wavelengths) / 10  # mA/cm2
Jph_Si = q * np.trapz(RAT["A_bulk"][0] * spectr_flux, wavelengths) / 10  # mA/cm2


pal = sns.cubehelix_palette(allres.shape[0], start=0.5, rot=-0.9)
pal.reverse()
cols = cycler("color", pal)
params = {"axes.prop_cycle": cols}

plt.rcParams.update(params)
# plot total R, A, T
fig = plt.figure(figsize=(5, 4))
ax = plt.subplot(111)
ax.plot(options["wavelength"] * 1e6, allres.T)
ax.set_xlabel(r"Wavelength ($\mu$m)")
ax.set_ylabel("Absorption/Emissivity")
ax.set_ylim(0, 1)
plt.legend(labels=["Ag", "Bulk Si", "GaAs 2", "GaAs 1", "R"])
plt.show()

print(Jph_GaAs_1, Jph_GaAs_2, Jph_Si)

profile_front = results[2][0]
profile_Si = results[3][0]
profile_back = results[2][1]

positions, absorb_fn = make_absorption_function(results, SC, options)

external_R = RAT["R"][0, :]

Si_SC = material("Si")
GaAs_SC = material("GaAs")
T = 300

p_material_Si = Si_SC(
    T=T, Na=si(1e21, "cm-3"), electron_diffusion_length=si("10um"), hole_mobility=50e-4, relative_permittivity=11.68
)
n_material_Si = Si_SC(
    T=T, Nd=si(1e16, "cm-3"), hole_diffusion_length=si("290um"), electron_mobility=400e-4, relative_permittivity=11.68
)


p_material_GaAs = GaAs_SC(
    T=T, Na=si(3e18, "cm-3"), electron_diffusion_length=si("400nm"), hole_mobility=50e-4, relative_permittivity=12.4
)
n_material_GaAs = GaAs_SC(
    T=T, Nd=si(1e18, "cm-3"), hole_diffusion_length=si("1um"), electron_mobility=100e-4, relative_permittivity=12.4
)

from solcore.solar_cell_solver import default_options as defaults_solcore

options_sc = defaults_solcore
options_sc.optics_method = "external"
options_sc.position = positions
options_sc.light_iv = True
options_sc.wavelength = wavelengths
options_sc.mpp = True
options_sc.theta = options.theta_in * 180 / np.pi
V = np.linspace(0, 2.5, 250)
options_sc.voltages = V

solar_cell = SolarCell(
    [
        Layer(50e-9, MgF2),
        Layer(40e-9, Ta2O5),
        Layer(30e-9, GaInP),
        Junction(
            [Layer(GaAs_1_th / 2, p_material_GaAs, role="emitter"), Layer(GaAs_1_th / 2, n_material_GaAs, role="base")],
            kind="DA",
        ),
        Layer(30e-9, InAlP),
        Layer(20e-9, GaAs),
        Layer(30e-9, GaInP),
        Junction(
            [Layer(150e-9, p_material_GaAs, role="emitter"), Layer(GaAs_2_th - 150e-9, n_material_GaAs, role="base")],
            kind="DA",
        ),
        Layer(30e-9, InAlP),
        Layer(100e-9, GaAs),
        Layer(6.5e-9, aSi_p),
        Layer(6.5e-9, aSi_i),
        Junction(
            [Layer(500e-9, p_material_Si, role="emitter"), Layer(250e-6 - 500e-9, n_material_Si, role="base")],
            kind="DA",
        ),
        Layer(6.5e-9, aSi_i),
        Layer(6.5e-9, aSi_n),
        Layer(240e-9, ITO_back),
    ],
    external_reflected=external_R,
    external_absorbed=absorb_fn,
)


solar_cell_solver(solar_cell, "qe", options_sc)
solar_cell_solver(solar_cell, "iv", options_sc)

plt.figure()
plt.plot(options["wavelength"] * 1e9, allres.T, color="grey")
plt.plot(wavelengths * 1e9, solar_cell.absorbed, "k--", label="Absorbed (integrated)")
plt.plot(wavelengths * 1e9, solar_cell[3].eqe(wavelengths), "r-", label="GaAs EQE")
plt.plot(wavelengths * 1e9, solar_cell[7].eqe(wavelengths), "b-", label="Si EQE")
plt.plot(wavelengths * 1e9, solar_cell[12].eqe(wavelengths), "g-", label="Si EQE")
plt.ylim(0, 1)
plt.legend()
plt.xlabel("Wavelength (nm)")
plt.ylabel("R/A")
plt.show()


plt.figure()
plt.plot(V, solar_cell.iv["IV"][1], "--k", label="Total")
plt.plot(V, -solar_cell[3].iv(V), "r", label="GaAs (1)")
plt.plot(V, -solar_cell[7].iv(V), "b", label="GaAs (2)")
plt.plot(V, -solar_cell[12].iv(V), "g", label="Si")
plt.ylim(-20, 250)
plt.xlim(0, 2.5)
plt.legend()
plt.ylabel("Current (A/m$^2$)")
plt.xlabel("Voltage (V)")  # The expected values of Isc and Voc are 372 A/m^2 and 0.63 V respectively
plt.show()