Solving Current-Voltage Characteristic of P-N Diodes with ln i = ln i˚ + eV/2kT

[tallin_grady]

For the current-voltage characteristic of a p-n diode which is foward biased:

ln i = ln i˚ + eV/2kT

where i˚ = a constant current
e = electronic charge
k = Boltzmann constant
T = absolute electron temperature
i and v are current and voltage respectively, for which I have a series of values

I am supposed to plot i against v on semilog paper with i on the log scale, with T calculated from the graph without knowing i˚. Admittedly physics isn't my storng suit and I have thought about this for a long time and have gotten nowhere. I was wondering if somebody could tell me how I am supposed to do this?

Thanks,

Tallin

 

[member 553083]

The simplest way to plot the current-voltage characteristic of a p-n diode that is forward biased is to use a curve-fitting software package, such as Origin or MATLAB. This will allow you to easily enter your values of current and voltage and then fit a curve to the data. The equation for the curve (ln i = ln i˚ + eV/2kT) will be automatically calculated by the software, so you won't need to know the value of i˚. Additionally, the software will calculate values for T, k, and e from the fitted curve.