On a rapidly converging iterative algorithm for diode parameter extraction from a single IV curve

We measure the I–V curve of a p–n diode on a range of currents where the well known Shockley model exhibits its shortcoming. We show that the behavior of the I–V curve, on the whole range of currents, can be captured by a modified four parameter Shockley model; the parameters of the model are obtained by a numerical procedure, consisting of an iterative rapidly converging nonlinear fitting algorithm. The fit returns sound estimates of the parameters for I–V curves, as function of temperature. The method is validated on a well known 1N4148 diode, but it can also be applied to any other devices described by single-diode models such as solar cells. We also show that the knowledge of the temperature dependence of the parameters can be used to obtain a quantitative estimate of other physical properties of the system, such as the energy gap of junction materials.