def mob_masetti_phos(N):
    """Return the mobility of carriers (cm²/Vs) in phosphorus doped silicon accoording to the model of Masetti1983.
    Where N is the doping (cm-3)
    http://dx.doi.org/10.1109%2FT-ED.1983.21207"""
    μmax = 1414
    μmin = 68.5
    u1 = 56.1
    Cr = 9.2e+16
    Cs = 3.41e+20
    a = 0.711
    b = 1.98
    return μmin + (μmax - μmin) / (1 + (N / Cr) ** a) - u1 / (1 + (Cs / N) ** b
        )
