# Schrodinger QW and MQW¶

In [ ]:
from solcore import si, material
from solcore.structure import Layer, Structure
import solcore.quantum_mechanics as QM


First we create the materials we need

In [ ]:
bulk = material("GaAs")(T=293, strained=False)
barrier = material("GaAsP")(T=293, P=0.1, strained=True)


As well as some of the layers

In [ ]:
top_layer = Layer(width=si("30nm"), material=barrier)
inter = Layer(width=si("3nm"), material=bulk)
barrier_layer = Layer(width=si("5nm"), material=barrier)
bottom_layer = top_layer


We create the QW material at the given composition

In [ ]:
QW = material("InGaAs")(T=293, In=0.15, strained=True)


And the layer

In [ ]:
well_layer = Layer(width=si("7.2nm"), material=QW)


The following lines create the QW structure, with different number of QWs and interlayers. Indicating the substrate material with the keyword "substrate" is essential in order to calculate correctly the strain.

A single QW with interlayers

In [ ]:
test_structure_1 = Structure([top_layer, inter, well_layer, inter, bottom_layer], substrate=bulk)
output_1 = QM.schrodinger(test_structure_1, quasiconfined=0, graphtype='potentials', num_eigenvalues=20, show=True)


10 QWs without interlayers

In [ ]:
test_structure_2 = Structure([top_layer, barrier_layer] + 10 * [well_layer, barrier_layer] + [bottom_layer],
substrate=bulk)
output_2 = QM.schrodinger(test_structure_2, quasiconfined=0.05, graphtype='potentialsLDOS', num_eigenvalues=200,
show=True)