TheAlgorithms-Python

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from math import log
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from scipy.constants import Boltzmann, physical_constants
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T = 300  # TEMPERATURE (unit = K)
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def builtin_voltage(
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    donor_conc: float,  # donor concentration
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    acceptor_conc: float,  # acceptor concentration
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    intrinsic_conc: float,  # intrinsic concentration
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) -> float:
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    """
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    This function can calculate the Builtin Voltage of a pn junction diode.
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    This is calculated from the given three values.
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    Examples -
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    >>> builtin_voltage(donor_conc=1e17, acceptor_conc=1e17, intrinsic_conc=1e10)
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    0.833370010652644
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    >>> builtin_voltage(donor_conc=0, acceptor_conc=1600, intrinsic_conc=200)
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    Traceback (most recent call last):
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      ...
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    ValueError: Donor concentration should be positive
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    >>> builtin_voltage(donor_conc=1000, acceptor_conc=0, intrinsic_conc=1200)
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    Traceback (most recent call last):
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      ...
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    ValueError: Acceptor concentration should be positive
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    >>> builtin_voltage(donor_conc=1000, acceptor_conc=1000, intrinsic_conc=0)
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    Traceback (most recent call last):
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      ...
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    ValueError: Intrinsic concentration should be positive
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    >>> builtin_voltage(donor_conc=1000, acceptor_conc=3000, intrinsic_conc=2000)
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    Traceback (most recent call last):
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      ...
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    ValueError: Donor concentration should be greater than intrinsic concentration
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    >>> builtin_voltage(donor_conc=3000, acceptor_conc=1000, intrinsic_conc=2000)
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    Traceback (most recent call last):
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      ...
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    ValueError: Acceptor concentration should be greater than intrinsic concentration
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    """
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    if donor_conc <= 0:
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        raise ValueError("Donor concentration should be positive")
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    elif acceptor_conc <= 0:
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        raise ValueError("Acceptor concentration should be positive")
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    elif intrinsic_conc <= 0:
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        raise ValueError("Intrinsic concentration should be positive")
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    elif donor_conc <= intrinsic_conc:
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        raise ValueError(
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            "Donor concentration should be greater than intrinsic concentration"
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        )
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    elif acceptor_conc <= intrinsic_conc:
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        raise ValueError(
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            "Acceptor concentration should be greater than intrinsic concentration"
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        )
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    else:
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        return (
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            Boltzmann
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            * T
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            * log((donor_conc * acceptor_conc) / intrinsic_conc**2)
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            / physical_constants["electron volt"][0]
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        )
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if __name__ == "__main__":
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    import doctest
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    doctest.testmod()
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