Setting up the options for and defining custom materials
========================================================

.. image:: Single_QW.png
   :width: 40%
.. image:: MQW_LDOS.png
   :width: 40%

.. code-block:: Python

    from solcore import si, material
    from solcore.structure import Layer, Structure
    import solcore.quantum_mechanics as QM

    # First we create the materials we need
    bulk = material("GaAs")(T=293, strained=False)
    barrier = material("GaAsP")(T=293, P=0.1, strained=True)

    # As well as some of the layers
    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
    QW = material("InGaAs")(T=293, In=0.15, strained=True)

    # And the layer
    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
    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
    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)