# pymatgen.analysis.solar package

Modules for prediciting theoretical solar-cell efficiency.

## Submodules

## pymatgen.analysis.solar.slme module

Calculate spectroscopy limited maximum efficiency (SLME) given dielectric function data.

Forked and adjusted from : https://github.com/usnistgov/jarvis

References: 1) https://doi.org/10.1021/acs.chemmater.9b02166 &

  2. https://doi.org/10.1103/PhysRevLett.108.068701

absorption_coefficient(dielectric)

  Calculate the optical absorption coefficient from an input set of pymatgen vasprun dielectric constant data.

  Parameters:

    dielectric (list) – A list containing the dielectric response function in the pymatgen vasprun format. - element 0: list of energies - element 1: real dielectric tensors, in `[xx, yy, zz, xy, xz, yz]` format. - element 2: imaginary dielectric tensors, in `[xx, yy, zz, xy, xz, yz]` format.

  Returns:

    absorption coefficient using eV as frequency units (cm^-1).

  Return type:

    (np.array)

get_dir_indir_gap(run='')

  Get direct and indirect bandgaps for a vasprun.xml.

optics(path='')

  Helper function to calculate optical absorption coefficient.

parse_dielectric_data(data)

  Convert a set of 2D vasprun formatted dielectric data to the eigenvalues of each corresponding 3x3 symmetric numpy matrices.

  Parameters:

    data (list) – length N list of dielectric data. Each entry should be a list of `[xx, yy, zz, xy , xz, yz ]` dielectric tensor elements.

  Returns:

    a Nx3 numpy array. Each row contains the eigenvalues

      for the corresponding row in data.

  Return type:

    np.array

slme(material_energy_for_absorbance_data, material_absorbance_data, material_direct_allowed_gap, material_indirect_gap, thickness=5e-05, temperature=293.15, absorbance_in_inverse_centimeters=False, cut_off_absorbance_below_direct_allowed_gap=True, plot_current_voltage=False)

  Calculate the SLME.

  Parameters:

    - material_energy_for_absorbance_data – energy grid for absorbance data

    - material_absorbance_data – absorption coefficient in m^-1

    - material_direct_allowed_gap – direct bandgap in eV

    - material_indirect_gap – indirect bandgap in eV

    - thickness – thickness of the material in m

    - temperature – working temperature in K

    - absorbance_in_inverse_centimeters – whether the absorbance data is in the unit of cm^-1

    - cut_off_absorbance_below_direct_allowed_gap – whether to discard all absorption below bandgap

    - plot_current_voltage – whether to plot the current-voltage curve

  Returns:

    The calculated maximum efficiency.

to_matrix(xx, yy, zz, xy, yz, xz)

  Convert a list of matrix components to a symmetric 3x3 matrix. Inputs should be in the order xx, yy, zz, xy, yz, xz.

  Parameters:

    - xx (float) – xx component of the matrix.

    - yy (float) – yy component of the matrix.

    - zz (float) – zz component of the matrix.

    - xy (float) – xy component of the matrix.

    - yz (float) – yz component of the matrix.

    - xz (float) – xz component of the matrix.

  Returns:

    The matrix, as a 3x3 numpy array.

  Return type:

    (np.array)