InGaAs material doesn't work

[SerenaMa89]

Describe the bug
A clear and concise description of what the bug is.
when I want to use InGaAs when In=0.53 to cacluate IV and EQE, it doesn't work, which occurs an index error.

To Reproduce
Steps to reproduce the behavior:
import numpy as np
import matplotlib.pyplot as plt
import solcore.poisson_drift_diffusion as PDD

from solcore import siUnits, material, si
from solcore.interpolate import interp1d
from solcore.solar_cell import SolarCell
from solcore.structure import Junction, Layer
from solcore.solar_cell_solver import solar_cell_solver
from solcore.light_source import LightSource

all_materials = []

We need to build the solar cell layer by layer.

We start from the AR coating. In this case, we load it from an an external file

refl_nm = np.loadtxt("MgF-ZnS_AR.csv", unpack=True, delimiter=",")
ref = interp1d(x=siUnits(refl_nm[0], "nm"), y=refl_nm[1], bounds_error=False, fill_value=0)

T = 300

InP = material("InP")(Nd=siUnits(5e18, "cm-3")) # n+ emitter
InGaAs = material("InGaAs")(In=0.53, Na=siUnits(3e17, "cm-3")) # p base

solar_cell = SolarCell([
Junction([
Layer(width=siUnits(0.2, "um"), material=InP, role="emitter"), # 光照侧
Layer(width=siUnits(2, "um"), material=InGaAs, role="base") # 背面
],
sn=1e3, sp=1e3, T=300, kind='PDD',
interface_defects=[{
"interface": "InGaAsP / InP",
"type": "neutral",
"sigma_n": 1e-15,
"sigma_p": 1e-15,
"energy_level": -0.15,
"density": 1e12
}])
], T=T, R_series=0, reflectivity=ref, shading=0.08, cell_area=0.7 * 0.7 / 1e4)

wl = np.linspace(280, 1850, 700) * 1e-9

Set up the light source

lightsource = LightSource(source_type='standard', version='AM1.5g', x=wl,
output_units='photon_flux_per_m')

Calculate the EQE for the solar cell:

solar_cell_solver(solar_cell, 'qe', user_options={'wavelength': wl,
'da_mode': 'green',
'optics_method': 'TMM'
})

plt.figure(1)
plt.plot(wl * 1e9, solar_cell(0).eqe(wl) * 100, 'b', label='InGaAs QE', linewidth=2)

try:
if hasattr(solar_cell(0), 'layer_absorption'):
absorption = solar_cell(0).layer_absorption * 100
plt.fill_between(wl * 1e9, absorption, 0, alpha=0.3,
label='InGaAs Abs.', color='b')
except:
print("Absorption data not available for plotting")

plt.plot(wl * 1e9, 100 * (1 - solar_cell.reflected), '--k',
label="100 - Reflectivity", linewidth=1)

plt.legend()
plt.ylim(0, 100)
plt.ylabel('EQE (%)')
plt.xlabel('Wavelength (nm)')
plt.title('External Quantum Efficiency')
plt.grid(True, alpha=0.3)
plt.show()

V = np.linspace(-3, 0, 300)
internal_voltages = np.linspace(-4, 2, 400)

solar_cell_solver(solar_cell, 'iv', user_options={'light_source': lightsource,
'voltages': V,
'internal_voltages': internal_voltages,
'light_iv': True,
'wavelength': wl,
'optics_method': 'TMM',
'mpp': True,
})

plt.figure(2)
plt.plot(abs(V), -solar_cell.iv['IV'][1] / 10, 'k', linewidth=3, label='Total IV')

plt.text(0.5, 30, f'Jsc= {abs(solar_cell.iv.Isc / 10):.2f} mA.cm' + r'$^{-2}$')
plt.text(0.5, 28, f'Voc= {abs(solar_cell.iv.Voc):.2f} V')
plt.text(0.5, 26, f'FF= {solar_cell.iv.FF * 100:.2f} %')
plt.text(0.5, 24, f'Eta= {solar_cell.iv.Eta * 100:.2f} %')

plt.legend()
plt.ylim(0, 35)
plt.xlim(0, 3)
plt.ylabel('Current (mA/cm$^2$)')
plt.xlabel('Voltage (V)')
plt.title('Current-Voltage Characteristics')
plt.grid(True, alpha=0.3)
plt.show()

print("\n=== Solar Cell Performance ===")
print(f"Short-circuit current density (Jsc): {abs(solar_cell.iv.Isc / 10):.2f} mA/cm²")
print(f"Open-circuit voltage (Voc): {abs(solar_cell.iv.Voc):.3f} V")
print(f"Fill Factor (FF): {solar_cell.iv.FF * 100:.2f} %")
print(f"Efficiency (η): {solar_cell.iv.Eta * 100:.2f} %")
print(f"Maximum power point voltage (Vmpp): {solar_cell.iv.Vmpp:.3f} V")
print(f"Maximum power point current (Impp): {abs(solar_cell.iv.Impp / 10):.2f} mA/cm²")

Expected behavior
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Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Solcore Version [e.g. 22]

Additional context
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[phoebe-p]

I can set the In fraction of In to 0.53 in your code without issue. You will have to be more specific. Can you give a smaller example of the part of the code which doesn't run, and more details on the error? And which version of Solcore you are using?

[SerenaMa89]

I can set the In fraction of In to 0.53 in your code without issue. You will have to be more specific. Can you give a smaller example of the part of the code which doesn't run, and more details on the error? And which version of Solcore you are using?

My solcore version is 5.10.1, and here's my code (simple InP/InGaAs np junction), and errors says IndexError: index 4 is out of bounds for axis 0 with size 4:

import numpy as np
import matplotlib.pyplot as plt
import solcore.poisson_drift_diffusion as PDD

from solcore import siUnits, material, si
from solcore.interpolate import interp1d
from solcore.solar_cell import SolarCell
from solcore.structure import Junction, Layer
from solcore.solar_cell_solver import solar_cell_solver
from solcore.light_source import LightSource

all_materials = []

We need to build the solar cell layer by layer.

We start from the AR coating. In this case, we load it from an an external file

refl_nm = np.loadtxt("MgF-ZnS_AR.csv", unpack=True, delimiter=",")
ref = interp1d(x=siUnits(refl_nm[0], "nm"), y=refl_nm[1], bounds_error=False, fill_value=0)

T = 300

InP = material("InP")(Nd=siUnits(5e18, "cm-3")) # n+ emitter
InGaAs = material("InGaAs")(In=0.53, Na=siUnits(3e17, "cm-3")) # p base

solar_cell = SolarCell([
Junction([
Layer(width=siUnits(0.2, "um"), material=InP, role="emitter"), # 光照侧
Layer(width=siUnits(2, "um"), material=InGaAs, role="base") # 背面
],
sn=1e3, sp=1e3, T=300, kind='PDD',
interface_defects=[{
"interface": "InGaAsP / InP",
"type": "neutral",
"sigma_n": 1e-15,
"sigma_p": 1e-15,
"energy_level": -0.15,
"density": 1e12
}])
], T=T, R_series=0, reflectivity=ref, shading=0.08, cell_area=0.7 * 0.7 / 1e4)

wl = np.linspace(280, 1850, 700) * 1e-9

Set up the light source

lightsource = LightSource(source_type='standard', version='AM1.5g', x=wl,
output_units='photon_flux_per_m')

Calculate the EQE for the solar cell:

solar_cell_solver(solar_cell, 'qe', user_options={'wavelength': wl,
'da_mode': 'green',
'optics_method': 'TMM'
})

plt.figure(1)
plt.plot(wl * 1e9, solar_cell(0).eqe(wl) * 100, 'b', label='InGaAs QE', linewidth=2)

try:
if hasattr(solar_cell(0), 'layer_absorption'):
absorption = solar_cell(0).layer_absorption * 100
plt.fill_between(wl * 1e9, absorption, 0, alpha=0.3,
label='InGaAs Abs.', color='b')
except:
print("Absorption data not available for plotting")

plt.plot(wl * 1e9, 100 * (1 - solar_cell.reflected), '--k',
label="100 - Reflectivity", linewidth=1)

plt.legend()
plt.ylim(0, 100)
plt.ylabel('EQE (%)')
plt.xlabel('Wavelength (nm)')
plt.title('External Quantum Efficiency')
plt.grid(True, alpha=0.3)
plt.show()

[SerenaMa89]

I can set the In fraction of In to 0.53 in your code without issue. You will have to be more specific. Can you give a smaller example of the part of the code which doesn't run, and more details on the error? And which version of Solcore you are using?

Here's the complete error (I think it's about lack of n/k value):

IndexError Traceback (most recent call last)
Cell In[1], line 47
43 lightsource = LightSource(source_type='standard', version='AM1.5g', x=wl,
44 output_units='photon_flux_per_m')
46 # Calculate the EQE for the solar cell:
---> 47 solar_cell_solver(solar_cell, 'qe', user_options={'wavelength': wl,
48 'da_mode': 'green',
49 'optics_method': 'TMM'
50 })
53 plt.figure(1)
54 plt.plot(wl * 1e9, solar_cell(0).eqe(wl) * 100, 'b', label='InGaAs QE', linewidth=2)

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\solar_cell_solver.py:113, in solar_cell_solver(solar_cell, task, user_options)
107 if action is None:
108 raise ValueError(
109 "ERROR in 'solar_cell_solver' - Valid tasks are "
110 f"{list(ACTIONS_REGISTRY.keys())}."
111 )
--> 113 action(solar_cell, options)

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\solar_cell_solver.py:222, in solve_qe(solar_cell, options)
213 @register_action("qe")
214 def solve_qe(solar_cell, options):
215 """Calculates the QE of all the junctions
216
217 :param solar_cell: A solar_cell object
218 :param options: Options for the solvers
219 :return: None
220 """
--> 222 solve_optics(solar_cell, options)
224 print("Solving QE of the solar cell...")
225 for j in solar_cell.junction_indices:

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\solar_cell_solver.py:145, in solve_optics(solar_cell, options)
139 if method is None:
140 raise ValueError(
141 "ERROR in 'solar_cell_solver' - Valid optics methods are "
142 f"{list(OPTICS_METHOD_REGISTRY.keys())}."
143 )
--> 145 method(solar_cell, **options)
147 else:
148 getLogger().info(
149 "Already calculated reflection, transmission and absorption profile - "
150 "not recalculating. Set 'recalculate_absorption' to True in the options if "
151 "you want absorption to be calculated again."
152 )

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\optics\tmm.py:130, in solve_tmm(solar_cell, wavelength, position, BL_correction, theta, pol, zero_threshold, no_back_reflection, coherency_list, **kwargs)
127 profile_position = position[position < sum(full_stack.widths)]
129 print("Calculating RAT...")
--> 130 RAT = calculate_rat(
131 full_stack,
132 wavelength * 1e9,
133 angle=theta,
134 coherent=coherent,
135 coherency_list=coherency_list,
136 no_back_reflection=no_back_reflection,
137 pol=pol,
138 )
140 print("Calculating absorption profile...")
141 out = calculate_absorption_profile(
142 full_stack,
143 wavelength * 1e9,
(...) 151 RAT_out=RAT,
152 )

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\absorption_calculator\transfer_matrix.py:526, in calculate_rat(structure, wavelength, angle, pol, coherent, coherency_list, no_back_reflection, **kwargs)
522 else:
523 if coherent:
524 out_p = tmm.coh_tmm(
525 "p",
--> 526 stack.get_indices(wavelength),
527 stack.get_widths(),
528 angle * degree,
529 wavelength,
530 )
531 out_s = tmm.coh_tmm(
532 "s",
533 stack.get_indices(wavelength),
(...) 536 wavelength,
537 )
538 A_per_layer_p = tmm.absorp_in_each_layer(out_p)

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\absorption_calculator\transfer_matrix.py:184, in OptiStack.get_indices(self, wl)
181 n0 = 1
183 for i in range(self.num_layers):
--> 184 out.append(self.n_datai + self.k_datai * 1.0j)
186 # substrate irrelevant if no_back_reflection = True
187 if self.no_back_reflection:

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\absorption_calculator\transfer_matrix.py:45, in np_cache..wrapper(array)
43 return function(array)
44 else:
---> 45 return cached_wrapper(tuple(array))

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\absorption_calculator\transfer_matrix.py:38, in np_cache..cached_wrapper(hashable_array)
35 @lru_cache()
36 def cached_wrapper(hashable_array):
37 array = np.array(hashable_array)
---> 38 return function(array)

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\material_system\material_system.py:388, in BaseMaterial.n_interpolated(self, x)
386 y = np.interp(x, self.n_data[0], self.n_data[1])
387 else:
--> 388 x, y, self.critical_points_n = critical_point_interpolate.critical_point_interpolate(
389 self.n_data,
390 self.n_critical_points,
391 self.main_fraction,
392 x
393 )
395 return y

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\material_system\critical_point_interpolate.py:101, in critical_point_interpolate(data, critical_points, target_fraction, grid)
99 def critical_point_interpolate(data, critical_points, target_fraction, grid):
100 result_critical_points, (lower_fract, higher_fract), fraction_along =
--> 101 interpolate_critical_points(critical_points, target_fraction)
103 interpolate_from_lower = transform(
104 data[lower_fract],
105 from_critical_points=critical_points[lower_fract],
106 to_critical_points=result_critical_points)
107 interpolate_from_higher = transform(
108 data[higher_fract],
109 from_critical_points=critical_points[higher_fract],
110 to_critical_points=result_critical_points)

File ~\anaconda3\envs\solcore\Lib\site-packages\solcore\material_system\critical_point_interpolate.py:17, in interpolate_critical_points(critical_points, target)
15 target_index = fractions_available.searchsorted(target)
16 lower = fractions_available[target_index - 1]
---> 17 upper = fractions_available[target_index]
19 fraction_along = (target - lower) / (upper - lower)
20 lower_points = critical_points[lower]

IndexError: index 4 is out of bounds for axis 0 with size 4