Incorrect units pvlib.ivtools.sdm.fit_desoto

[RDaxini]

Is your feature request related to a problem? Please describe.
Units of dEg/dT in pvlib.ivtools.sdm.fit_desoto should be 1/K, not eV/K

Describe the solution you'd like
Correct the units

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Comment

Marking as good first issue for a new contributor, but I could fix this if no-one does it before 11.2 release if we want it done by then.

[RahulTripathi-04]

You'll first need to understand where the function fit_desoto defines or calculates the temperature dependence of the parameter(s) in question. Specifically, the part where the function outputs values related to temperature and currently uses the eV/K unit.

*. Check the Calculation of Temperature Coefficient
Look for any lines of code where the temperature coefficient is computed. The temperature coefficient is typically a factor that relates how a certain physical property (e.g., current, voltage, or efficiency) changes with temperature.
If the coefficient is currently expressed in eV/K, you'll likely find something like this:
python
Copy code
temperature_coefficient = some_value * (energy_in_eV) / temperature_change

• Modify the Calculation to Use 1/K
  To change the units from eV/K to 1/K, you'll need to remove any energy-related term (like eV) from the calculation. The temperature coefficient should just be a dimensionless quantity, indicating the relative change per Kelvin.

For example, if the code currently uses eV/K, you could modify it as follows:

code
"temperature_coefficient = some_value / temperature_change " # where temperature_change is in Kelvin
The new calculation should ensure that the coefficient is in 1/K, rather than eV/K.

[cwhanse]

To clarify: the unit in the docstring is given as eV/K, it should be 1/K, per discussion in #2154. No other change is needed.