9-13 July 2012
Extracting device parameters of pn-junction diodes using sigmoidal properties of resistance – voltage curves: theory, simulation and application
Presented by Ms. Pesi HANGOMA on 12 Jul 2012 from 08:20 to 08:40
Type: Oral Presentation
Track: Track A - Division for Condensed Matter Physics and Materials
Current-voltage (I-V) curves of pn-junction diodes obtained at a known temperature T are often characterised using the non-ideal diode model of diodes having an ideality factor k, reverse saturation current Io, series resistance Rs and shunt resistance Rsh. The graph of diode resistance R against bias potential V is sigmoidal with a singularity at V=0 so that diode resistance at V=0 is obtained only as a limit for V approaching 0. The Lambert W function is used to obtained analytic expressions forI, V and R. An injective logarithmic mapping function is then used to transform the analytic expression for R to avoid the singularity at V=0. The resulting injective multidimensional expression for R is finally optimised to fit experimentally determined resistance values for germanium curves, using the Levenberg-Marquardt method.
Mr. Nchimunya Mwiinga