def test_tighter_confinement_leads_to_higher_energy_states():
"""Tests that a smaller CSNC leads to higher-energy eigenstates.
"""
a = Material(2.0, 0.0, 1.0, 1.0, 1.0)
b = Material(1.0, -0.5, 1.0, 1.0, 1.0) # Lower band edges.
csnc1 = CoreShellParticle(b, a, 1.0, 1.0) # Type 1 CSNC.
csnc2 = CoreShellParticle(b, a, 0.9, 1.0) # Type 1 CSNC.
csnc1_energies = csnc1.calculate_s1_energies()
csnc2_energies = csnc2.calculate_s1_energies()
assert np.all(csnc2_energies > csnc1_energies)
def main():
inp_effective_electron_mass = 0.073
InP = Material(1.34, 0, inp_effective_electron_mass, 0.64, 9.6, "InP")
CdS = Material(2.20, -0.39, 0.21, 0.68, 5.3, "CdS")
shell_widths = np.array([0.53, 1.05, 1.47, 1.90, 2.76, 3.84])
experimental_bandgaps = [1.78, 1.46, 1.37, 1.32, 1.26, 1.24]
print("Using InP electron effective mass: {:0.2f}".format(
inp_effective_electron_mass))
print(
"Core \t Shell \tExp \t BG \t E(e): E(h): Coulomb: Polarization: Model(Exp-Model):"
)
for i, shell_width in enumerate(shell_widths):
csnc = CoreShellParticle(InP, CdS, 1.23, shell_width, 1.5)
print(1.23, "\t", shell_width, end="\t")
# print("Is CSNC type two? h/e?", csnc.type_two, csnc.h_e)
energies = np.array(csnc.calculate_s1_energies())
# print(energies)
plots = False
col_energy_sectioned = csnc.coulomb_screening_energy(
plot_integrand=plots)
pol_energy_sectioned = csnc.polarization_screening_energy(
plot_integrand=plots)
self_energy = csnc.self_interaction_energy()
# print(xx_coulomb_sectioned)
# whole_integral_energy = (
# csnc.bandgap + np.sum(energies) + col_energy_whole[0] + pol_energy_whole[0]
# )
sectioned_integral_energy = (
csnc.bandgap + np.sum(energies) + col_energy_sectioned[0] +
pol_energy_sectioned[0] # + self_energy
) # + xx_coulomb_sectioned[0]
# print("Col:", col_energy_whole, col_energy_sectioned, "Pol:", pol_energy)
# print("NC bandgap:", csnc.bandgap)
print(experimental_bandgaps[i], end="\t")
# print(
# "{:0.2f}({:0.2f})".format(
# whole_integral_energy,
# abs(experimental_bandgaps[i] - whole_integral_energy),
# ),
# end="\t",
# )
print(
"{:0.3f}\t{:0.3f}\t{:0.3f}\t{:0.3f}\t{:0.3f}\t{:0.3f}\t{:0.3f}".
format(
csnc.bandgap,
energies[0],
energies[1],
col_energy_sectioned[0],
pol_energy_sectioned[0],
sectioned_integral_energy,
experimental_bandgaps[i] - sectioned_integral_energy,
),
end="\t",
)
print()
def test_energies_are_order_unity():
"""Tests that energies are approximately around 1.
"""
a = Material(1.0, 0.0, 1.0, 1.0, 1.0)
b = Material(1.0, -0.5, 1.0, 1.0, 1.0) # Lower band edges.
csnc1 = CoreShellParticle(a, b, 1.0, 1.0) # Type 2 CSNC. h/e structure.
energies = csnc1.calculate_s1_energies()
assert np.all(np.logical_and(1e-1 < energies, energies < 10))
def test_adaptive_energy_bracketing_for_high_energies():
"""Tests that high energies are bracketed for extremely small CSNCs.
"""
a = Material(1.0, 0.0, 1.0, 1.0, 1.0)
b = Material(1.0, -0.5, 1.0, 1.0, 1.0) # Lower band edges.
csnc1 = CoreShellParticle(a, b, 0.1, 0.1) # Type 2 CSNC. h/e structure.
energies = csnc1.calculate_s1_energies()
# print(energies)
assert np.isclose(energies[0], energies[1])
import numpy as np
from pyncband import Material, CoreShellParticle
InP = Material(1.34, 0, 1.0, 0.64, 9.6, "InP")
CdS = Material(2.20, -0.39, 0.21, 0.68, 5.3, "CdS")
def inp_electron_mass_from_energy(e):
alpha = -1.2
e_p = 20.6
e_g = 1.34
return 1 / (alpha + e_p / (e_g + e))
for energy in np.linspace(0.1, 1, 5):
print(inp_electron_mass_from_energy(energy))
inp_eff_electron_mass = 1.0
mass_eps = 1.0
print("Iteratively figuring out InP electron effective mass:")
while mass_eps > 1e-5:
InP = Material(1.34, 0, inp_eff_electron_mass, 0.64, 9.6, "InP")
csnc = CoreShellParticle(InP, CdS, 1.23, 1.90, 1.5)
energy_e, energy_h = csnc.calculate_s1_energies()
inp_eff_electron_mass_new = inp_electron_mass_from_energy(energy_e)
mass_eps = abs(inp_eff_electron_mass_new - inp_eff_electron_mass)
print(mass_eps, inp_eff_electron_mass, inp_eff_electron_mass_new)
inp_eff_electron_mass = inp_eff_electron_mass_new